Proportional Reasoning with Ratios and Rates

UNIT 1: Proportional Reasoning with Ratios and Rates


PART 1: INTRO TO RATIOS


1. Basic Ratios

Description:
A ratio compares two quantities. It tells us how much of one thing there is compared to another. Ratios can compare part to part or part to whole.

Explanation (TEKS 6.4C & 6.4D):
Write ratios in three ways:

  • Using "to" → 3 to 5

  • Using a colon → 3:5

  • As a fraction → 3/5

Critical rule: Keep the order exactly as the problem asks.

  • "Ratio of boys to girls" is different from "ratio of girls to boys"

Example 1:

A class has 8 boys and 12 girls.

Ratio of boys to girls = 8 to 12 = 8:12 = 8/12 (simplifies to 2/3)

Ratio of girls to boys = 12 to 8 = 12:8 = 12/8 (simplifies to 3/2)

Ratio of boys to total students (part to whole) = 8 to 20 = 8:20 = 8/20

Example 2:

A fruit basket has 6 apples and 4 oranges.

Ratio of apples to oranges = 6:4 = 3:2 (simplified)

Ratio of oranges to total fruit = 4:10 = 2:5

Practice Questions (Basic Ratios):

  1. A pet store has 15 dogs and 10 cats. Write the ratio of dogs to cats in simplest form.

  2. A recipe uses 2 cups of flour and 3 cups of sugar. Write the ratio of flour to sugar as a fraction.

  3. In a bag, there are 7 red marbles, 5 blue marbles, and 8 green marbles. What is the ratio of blue marbles to total marbles?

  4. A soccer team scored 12 goals and allowed 8 goals. Write the ratio of goals scored to goals allowed using a colon.

  5. A parking lot has 24 cars and 6 trucks. What is the ratio of trucks to cars in simplest form?


2. Ratios as Fractions and Decimals

Description:
A ratio written as a fraction can also be converted to a decimal. This helps when comparing ratios or working with real-world measurements.

Explanation:

  • A ratio of a:b means a/b

  • To convert fraction to decimal: divide numerator by denominator

  • The decimal represents the relative size of one quantity to another

Example 1:

Ratio of 3:4 as fraction = 3/4
3/4 as decimal = 3 ÷ 4 = 0.75

Example 2:

A class has 5 boys for every 8 students.
Ratio = 5:8
Fraction = 5/8
Decimal = 5 ÷ 8 = 0.625
This means 62.5% of the class are boys.

Example 3:

In a juice mix, ratio of concentrate to water is 1:3.
Fraction of concentrate = 1/4 = 0.25
Fraction of water = 3/4 = 0.75

Practice Questions (Ratios as Fractions and Decimals):

  1. Write the ratio 7:10 as a fraction and as a decimal.

  2. A recipe has a ratio of oil to vinegar of 2:5. What fraction of the mixture is oil? What is that as a decimal?

  3. In a game, the ratio of wins to losses is 9:6. Simplify the ratio, write as a fraction, then convert to decimal.

  4. A school has 240 boys and 360 girls. What decimal represents the ratio of boys to girls?

  5. A paint mixture has a ratio of blue to white paint of 3:8. What fraction and decimal represent the amount of blue paint compared to white paint?


✅ QUIZ 1: Basic Ratios + Ratios as Fractions/Decimals

  1. A zoo has 24 lions, 18 tigers, and 30 bears. Write the ratio of tigers to total animals.

  2. Convert the ratio 5:8 to a decimal.

  3. In a box, the ratio of pens to pencils is 9:15. Simplify and write as a fraction.

  4. A basketball team made 18 free throws and missed 12. What is the ratio of made to missed as a decimal?

  5. A punch recipe uses 2 parts orange juice to 3 parts soda. What fraction of the punch is orange juice?


PART 2: VISUALIZE EQUIVALENT RATIOS


3. Ratios with Tape Diagrams

Description:
A tape diagram is a visual tool that uses rectangular strips (tapes) to represent quantities. Each "tape" represents an equal part. This helps see the relationship between quantities.

Explanation (TEKS 6.5A):

  • Draw rectangles (tapes) for each part of the ratio

  • Each rectangle has the same size (equal groups)

  • Label each tape with its quantity

  • Use total to find the value of one tape

Example 1:

The ratio of red to blue marbles is 3:2. There are 15 red marbles. How many blue marbles?

Step 1: Draw 3 tapes for red, 2 tapes for blue
Step 2: 3 tapes = 15 marbles → 1 tape = 5 marbles
Step 3: Blue has 2 tapes → 2 × 5 = 10 blue marbles

Example 2:

Ratio of boys to girls is 4:5. Total students = 36. How many boys?

Step 1: Total tapes = 4 + 5 = 9 tapes
Step 2: 9 tapes = 36 students → 1 tape = 4 students
Step 3: Boys have 4 tapes → 4 × 4 = 16 boys

Example 3:

The ratio of flour to sugar is 3:1. If there are 12 cups of flour, how much sugar?

3 tapes = 12 cups → 1 tape = 4 cups
Sugar = 1 tape = 4 cups

Practice Questions (Ratios with Tape Diagrams):

  1. Ratio of cats to dogs is 2:3. There are 8 cats. How many dogs? Draw a tape diagram.

  2. Ratio of apples to oranges is 5:2. Total fruits = 49. How many apples?

  3. In a bag, ratio of pennies to nickels is 4:1. There are 20 pennies. How many nickels?

  4. Ratio of adults to children at a movie is 3:7. There are 60 adults. How many children?

  5. A school's ratio of teachers to students is 1:25. Total people = 520. How many teachers?


4. Equivalent Ratios with Equal Groups

Description:
Equivalent ratios are different ratios that represent the same relationship. You find them by multiplying or dividing both parts of a ratio by the same nonzero number.

Explanation:

  • Multiply or divide the numerator and denominator by the same number

  • Like finding equivalent fractions

  • 2:3 is equivalent to 4:6, 6:9, 8:12, etc.

Example 1:

Find 3 equivalent ratios to 4:5

Multiply by 2: 8:10
Multiply by 3: 12:15
Multiply by 4: 16:20

Example 2:

Are 6:9 and 10:15 equivalent?

Simplify 6:9 = ÷3 → 2:3
Simplify 10:15 = ÷5 → 2:3
Yes, they are equivalent (both simplify to 2:3)

Example 3:

Find the missing value: 3:7 = 9:x

3 × 3 = 9, so multiply 7 × 3 = 21
x = 21

Practice Questions (Equivalent Ratios with Equal Groups):

  1. Write three equivalent ratios to 2:5.

  2. Are 8:12 and 14:21 equivalent? Show your work.

  3. Find the missing value: 5:6 = 15:x

  4. Write the simplest form of 18:24.

  5. A ratio is 7:9. Write an equivalent ratio where the first term is 21.


5. Create Double Number Lines

Description:
A double number line has two parallel lines with matching tick marks. The top line shows one quantity, the bottom line shows the related quantity. It helps visualize scaling ratios.

Explanation:

  • Draw two parallel lines

  • Mark 0 on both lines at the left

  • Place given ratio on matching tick marks

  • Add more tick marks by adding the same increments

Example 1:

Create a double number line for the ratio 2:3 (miles to hours)

Top (miles): 0, 2, 4, 6, 8
Bottom (hours): 0, 3, 6, 9, 12
(Each step adds 2 miles and 3 hours)

Example 2:

A recipe uses 1 cup of sugar for every 4 cups of flour. Create a double number line for 0 to 5 cups of sugar.

Sugar: 0, 1, 2, 3, 4, 5
Flour: 0, 4, 8, 12, 16, 20

Practice Questions (Create Double Number Lines):

  1. Create a double number line for the ratio 3:5. Show 4 increments beyond the given ratio.

  2. A car travels 30 miles per hour. Create a double number line for time (hours) and distance (miles) from 0 to 4 hours.

  3. For ratio 4:7, what is the bottom number when the top is 12? (Use double number line reasoning)

  4. A paint mix uses 2 drops of blue for every 5 drops of yellow. Create a double number line from 0 to 8 drops of blue.

  5. On a map, 1 inch represents 10 miles. Create a double number line from 0 to 5 inches.


6. Ratios with Double Number Lines

Description:
Using a pre-drawn or self-created double number line to find missing values in a proportional relationship.

Explanation:

  • Find the scale factor (how much you multiply to go from one known value to another)

  • Apply same scale factor to the other quantity

  • Or count increments on the double number line

Example 1:

On a double number line: Top (cups flour): 0, 2, 4, 6; Bottom (cups sugar): 0, 1, 2, 3
How much sugar for 10 cups flour?

10 is 5 increments of 2 → 5 × 1 = 5 cups sugar

Example 2:

Ratio is 3 tickets for $12. How much for 5 tickets?

Tickets: 0, 3, 6, 9...
Cost ($): 0, 12, 24, 36...
Find 5 tickets: between 3 and 6. Use proportional: 3 tickets = $12, so 1 ticket = $4, 5 tickets = $20

Practice Questions (Ratios with Double Number Lines):

  1. On a double number line, 4 apples cost $2. How much for 10 apples?

  2. A runner runs 6 miles in 48 minutes. At this rate, how long for 9 miles?

  3. On a double number line, 5 notebooks cost $7.50. How many notebooks for $15?

  4. A recipe uses 2 eggs for 3 cups of flour. How many eggs for 12 cups of flour?

  5. A bike travels 15 miles in 1 hour. Use a double number line to find distance in 2.5 hours.


7. Relate Double Number Lines and Ratio Tables

Description:
Ratio tables and double number lines show the same information in different formats. You can convert between them. A ratio table organizes equivalent ratios in rows/columns.

Explanation:

  • Double number line → Ratio table: List each tick mark pair as a row

  • Ratio table → Double number line: Plot each row as a point on two lines

  • Both show multiplicative relationships

Example 1:

Double number line:
Hours: 0, 1, 2, 3, 4
Miles: 0, 50, 100, 150, 200

Ratio table:

HoursMiles
150
2100
3150
4200

Example 2:

Ratio table:

xy
26
412
618

This is ratio 2:6 = 1:3. Double number line: top (x): 0,2,4,6; bottom (y): 0,6,12,18

Practice Questions (Relate Double Number Lines and Ratio Tables):

  1. Convert this double number line to a ratio table: Top (cups water): 0, 3, 6, 9; Bottom (cups rice): 0, 1, 2, 3

  2. Convert this ratio table to a double number line (describe the tick marks):

    PacketsSeeds
    120
    240
    360
  3. A double number line shows 5 meters = 2 seconds. Create a ratio table for 10, 15, and 20 meters.

  4. From a ratio table, how do you know if the relationship is proportional?

  5. The ratio table shows 3 pens cost $4.50. Draw what the double number line would look like for 0, 3, 6, 9 pens.


✅ QUIZ 2: Visualize Equivalent Ratios

(Topics: Tape diagrams, equal groups, double number lines, relating tables and lines)

  1. Draw a tape diagram for ratio 4:7 where the smaller quantity is 12. Find the larger quantity.

  2. Find the missing value: 3:8 = 9:x

  3. Create a double number line for 2 gallons of paint covering 500 square feet. Show up to 10 gallons.

  4. Convert this ratio table to a double number line: Minutes: 0, 5, 10, 15; Words typed: 0, 75, 150, 225

  5. Is 5:8 equivalent to 15:20? Explain.


PART 3: EQUIVALENT RATIOS


8. Ratio Tables

Description:
A ratio table is an organized way to list equivalent ratios. Each column (or row) shows a pair of numbers that keep the same multiplicative relationship.

Explanation:

  • Multiply or divide both terms by the same number to get a new column

  • Use ratio tables to solve problems with missing values

  • Also called "proportional tables" on STAAR

Example 1:

Complete the ratio table for the ratio 2:3

246810
3691215
(Multiply both by 1,2,3,4,5)

Example 2:

Find the missing value:

51015x
8162432

Pattern: multiply top by 1.6 (or bottom ÷ top = 1.6)
x = 20 because 32 ÷ 1.6 = 20

Practice Questions (Ratio Tables):

  1. Complete the ratio table for ratio 4:9:

4

8

12

16

9


27


  1. Find the missing value:

3

6

9

15

7

14

21

x

  1. A recipe uses 2 cups flour to 5 cups milk. Complete the table:

flour

2

4

6

10

Milk

5


15


  1. Is this a proportional ratio table? Explain:

1

2

4

8

3

6

12

20

5. Create a ratio table for the ratio 7:2 showing 4 equivalent ratios.

9. Equivalent Ratios

Description:
Equivalent ratios represent the same relationship between quantities. You can find them by multiplying or dividing both terms by the same number (scale factor).

Explanation:

  • Scale factor = new value ÷ original value

  • Multiply BOTH terms by the scale factor

  • Or find the simplest form (like simplifying fractions)

Example 1:

Are 6:10 and 9:15 equivalent?

Method 1: Simplify 6:10 = 3:5; 9:15 = 3:5 → Yes
Method 2: Cross-multiply: 6×15 = 90, 10×9 = 90 → Yes

Example 2:

Find an equivalent ratio to 8:20

Simplify: ÷4 → 2:5
Multiply: ×3 → 24:60

Practice Questions (Equivalent Ratios):

  1. Are 4:7 and 12:21 equivalent? Prove your answer.

  2. Find three equivalent ratios to 9:12.

  3. Simplify 25:35 to lowest terms.

  4. Which ratio is NOT equivalent to 5:8? A) 10:16 B) 15:24 C) 20:30 D) 25:40

  5. A ratio is 6:14. Write an equivalent ratio where the second term is 35.


10. Equivalent Ratio Word Problems

Description:
Real-world problems where you must find a missing value using equivalent ratios. Often involves recipes, mixtures, speeds, or prices.

Explanation (TEKS 6.4B - Readiness Standard):

  • Identify the two quantities being compared

  • Set up a proportion: known ratio = unknown ratio

  • Solve by cross-multiplication or scale factor

Strategy:

  1. Write what you know as a ratio (simplify if helpful)

  2. Write what you need to find with a variable

  3. Cross-multiply: a/b = c/d → a×d = b×c

  4. Solve for the variable

Example 1:

A recipe calls for 3 cups of flour for every 2 cups of sugar. How much sugar is needed for 9 cups of flour?

Ratio: flour:sugar = 3:2
3/2 = 9/x
Cross-multiply: 3×x = 2×9 → 3x = 18 → x = 6 cups sugar

Example 2:

On a map, 2 inches represent 15 miles. How many miles are represented by 5 inches?

2/15 = 5/x → 2x = 75 → x = 37.5 miles

Example 3:

A factory produces 240 toys in 4 hours. At this rate, how many toys in 7 hours?

240/4 = x/7 → 4x = 1680 → x = 420 toys

Practice Questions (Equivalent Ratio Word Problems):

  1. A smoothie uses 2 bananas for every 3 cups of yogurt. How many bananas for 9 cups of yogurt?

  2. A car travels 210 miles on 7 gallons of gas. How far on 10 gallons?

  3. A recipe for 8 muffins uses 2 cups of flour. How much flour for 20 muffins?

  4. The ratio of boys to girls in a club is 3:5. If there are 24 boys, how many girls?

  5. A printer prints 45 pages in 3 minutes. At this rate, how many minutes for 120 pages?


11. Equivalent Ratios in the Real World

Description:
Applying equivalent ratios to everyday situations like shopping (unit price), cooking (scaling recipes), mixing (paint or concrete), and maps (scale drawings).

Explanation:

  • Look for the "per one" relationship (unit rate)

  • Use that unit rate to solve for any quantity

  • Real-world problems often require rounding or interpreting remainders

Example 1 (Shopping):

A 12-ounce box costs $3.60. A 20-ounce box costs $5.80. Which is the better buy?

Unit price: $3.60 ÷ 12 = $0.30 per ounce
$5.80 ÷ 20 = $0.29 per ounce
The 20-ounce box is cheaper per ounce.

Example 2 (Scaling a recipe):

A recipe for 4 servings uses 1.5 cups of broth. How much broth for 10 servings?

1.5/4 = x/10 → 4x = 15 → x = 3.75 cups

Practice Questions (Real-World Equivalent Ratios):

  1. A 6-pack of water bottles costs $4.50. A 12-pack costs $8.40. Which is the better unit price?

  2. Concrete is mixed with 1 part cement to 3 parts sand. How much cement for 45 pounds of sand?

  3. A photo is 4 inches wide and 6 inches tall. If enlarged to 10 inches wide, how tall will it be?

  4. A map scale is 1 cm = 5 km. Two cities are 8 cm apart on the map. How far apart in reality?

  5. A juice blend uses 2 parts orange to 5 parts apple juice. To make 14 cups of blend, how many cups of orange juice?


12. Understand Equivalent Ratios in the Real World

Description:
Moving beyond just computing to interpreting what equivalent ratios mean in context. This includes explaining why two ratios are equivalent and using reasoning to compare situations.

Explanation:

  • Understanding "per" statements (miles per hour, price per pound)

  • Recognizing constant of proportionality (k = y/x)

  • Explaining why a real-world relationship is proportional

Example 1:

"A car travels 120 miles in 2 hours." This means 60 miles per hour. The ratio is constant: 240 miles in 4 hours, 360 in 6 hours.

Example 2:

Two mixtures: Mix A has 2 tsp salt to 5 cups water. Mix B has 3 tsp salt to 8 cups water. Which is saltier?

Mix A: 2/5 = 0.4 tsp per cup
Mix B: 3/8 = 0.375 tsp per cup
Mix A is saltier (higher ratio of salt to water).

Practice Questions (Understand Equivalent Ratios):

  1. Explain why 4:6 and 8:12 are equivalent ratios using words.

  2. A store sells 3 shirts for $45. Another store sells 5 shirts for $70. Which is the better deal? Explain.

  3. Two paint mixtures: Mix X (2 blue:3 white), Mix Y (3 blue:5 white). Which is bluer? Explain.

  4. "This car gets 25 miles per gallon." What does this mean? Write two equivalent ratios.

  5. A student says 3:5 is equivalent to 9:20. Is she correct? Explain why or why not.


✅ QUIZ 3: Equivalent Ratios

  1. Complete: | 3 | 9 | 15 | 21 |
    |---|---|---|---|
    | 4 | 12 | | |

  2. Are 7:11 and 21:33 equivalent? Show work.

  3. A factory produces 300 widgets in 5 hours. How many in 8 hours?

  4. Which is the better buy: 10 pencils for $2.50 or 16 pencils for $3.68?

  5. A map scale is 0.5 inch = 20 miles. How many miles for 3 inches?


PART 4: RATIO APPLICATION


13. Ratios on Coordinate Plane

Description:
Plotting ratio pairs as points (x, y) on a coordinate grid. For equivalent ratios, the points will lie on a straight line that passes through the origin (0,0).

Explanation (TEKS 6.4A):

  • Each ratio pair (a, b) becomes point (a, b)

  • For equivalent ratios, all points are collinear with (0,0)

  • The slope of the line = constant of proportionality (b/a)

Example 1:

Plot points for ratio 1:2 → (1,2), (2,4), (3,6), (4,8)
All points lie on line y = 2x through (0,0)

Example 2:

Which points represent equivalent ratios to 2:3?
(4,6) → 4/6 = 2/3 ✓
(6,9) → 6/9 = 2/3 ✓
(3,4) → 3/4 = 0.75, not 2/3 ✗

Practice Questions (Ratios on Coordinate Plane):

  1. Plot these points from a ratio table: (1,5), (2,10), (3,15). Do they form a straight line? What is the ratio?

  2. Is (4,10) equivalent to ratio 2:5? Explain.

  3. A point (6,9) lies on a proportional line. What is the missing point if x=8?

  4. Graph the ratio 3:4 from x=1 to x=4. Describe the line.

  5. Two points are (2,6) and (5,15). Are they on a proportional line? What is the constant?


14. Ratios and Units of Measurement

Description:
Using ratios to convert between different units of measurement (customary and metric). Requires knowing conversion factors.

Explanation:

  • Write conversion factor as a ratio equal to 1 (e.g., 12 inches/1 foot)

  • Multiply the given quantity by the conversion ratio

  • Cancel units to get desired unit

Example 1:

Convert 3 feet to inches
3 ft × (12 in / 1 ft) = 36 inches

Example 2:

A snake is 60 inches long. How many feet?
60 in × (1 ft / 12 in) = 5 feet

Example 3:

A car travels 2 miles per minute. How many feet per second?
Step 1: 2 miles/min × 5280 ft/mile = 10,560 ft/min
Step 2: 10,560 ft/min ÷ 60 sec/min = 176 ft/sec

Practice Questions (Ratios and Units of Measurement):

  1. Convert 5 yards to feet. (1 yd = 3 ft)

  2. Convert 48 ounces to pounds. (1 lb = 16 oz)

  3. A recipe calls for 2 liters of water. How many milliliters? (1 L = 1000 mL)

  4. A runner runs 6 meters per second. How many meters per minute?

  5. Convert 2.5 hours to minutes.


15. Part-Part-Whole Ratios

Description:
Ratios that compare two parts to each other (part-part) or a part to the whole (part-whole). Often used with tape diagrams.

Explanation:

  • Part + Part = Whole

  • If ratio of part A : part B = a:b, then:

    • Part A = (a/(a+b)) × Whole

    • Part B = (b/(a+b)) × Whole

    • Whole : Part A = (a+b):a

Example 1:

Ratio of cats to dogs is 3:4. Total animals = 28.
Total parts = 3+4 = 7
Each part = 28 ÷ 7 = 4 animals
Cats = 3 × 4 = 12, Dogs = 4 × 4 = 16

Example 2:

Ratio of red to blue marbles is 5:2. There are 20 red marbles. How many total marbles?
5 parts = 20 → 1 part = 4
Blue = 2 × 4 = 8
Total = 20 + 8 = 28 marbles

Practice Questions (Part-Part-Whole Ratios):

  1. Ratio of boys to girls is 2:3. There are 30 students total. How many boys?

  2. Ratio of apples to oranges is 5:1. There are 25 apples. How many total fruits?

  3. In a bag, ratio of quarters to dimes is 3:4. There are 21 dimes. How many total coins?

  4. A class has 18 girls. Ratio of boys to girls is 4:9. How many total students?

  5. Ratio of fiction to nonfiction books is 7:2. There are 49 fiction books. How many total books?


✅ QUIZ 4: Ratio Application

  1. Plot these points: (1,4), (2,8), (3,12). What is the ratio? Do they form a line through origin?

  2. Convert 7 gallons to quarts. (1 gal = 4 qt)

  3. Convert 150 centimeters to meters. (100 cm = 1 m)

  4. Ratio of blue to red marbles is 4:5. Total marbles = 54. How many blue?

  5. Ratio of left-handed to right-handed students is 1:8. There are 36 right-handed. How many total?


PART 5: INTRO TO RATES


16. Unit Rates

Description:
A rate is a ratio comparing two quantities with different units (e.g., miles per hour, price per pound). A unit rate has a denominator of 1.

Explanation (TEKS 6.4B & 6.5A):

  • To find unit rate: divide first quantity by second quantity

  • Unit rate = "per one" (something per 1 unit of something else)

  • Written as: $5 per pound, 60 miles per hour

Example 1:

240 miles in 4 hours → 240 ÷ 4 = 60 miles per hour (unit rate)

Example 2:

$12 for 3 pounds → 12 ÷ 3 = $4 per pound

Example 3:

120 words in 2 minutes → 60 words per minute

Practice Questions (Unit Rates):

  1. Find the unit rate: 300 miles on 15 gallons.

  2. 24 ounces cost $6.00. What is the unit price per ounce?

  3. A plane flies 1,200 miles in 3 hours. What is the unit rate (speed)?

  4. 8 shirts cost $96. What is the cost per shirt?

  5. A machine produces 450 bottles in 5 hours. How many per hour?


17. Rate Problems

Description:
Word problems that involve rates. Usually ask: find total for a different quantity, or find time/distance given the rate.

Explanation:

  • Find the unit rate first

  • Then multiply by the new quantity

  • Or set up a proportion: rate1 = rate2

Example 1:

A car travels at 55 miles per hour. How far in 3.5 hours?
55 × 3.5 = 192.5 miles

Example 2:

A faucet fills a tub at 8 gallons per minute. How long to fill 120 gallons?
120 ÷ 8 = 15 minutes

Example 3:

A baker makes 24 cupcakes in 2 hours. At this rate, how many in 5 hours?
Unit rate = 12 cupcakes/hour → 12 × 5 = 60 cupcakes

Practice Questions (Rate Problems):

  1. A runner runs at 12 feet per second. How far in 10 seconds?

  2. A printer prints 30 pages per minute. How long for 450 pages?

  3. A car uses 0.05 gallons of gas per mile. How many gallons for 200 miles?

  4. A typist types 45 words per minute. How many words in 20 minutes?

  5. A water pump moves 15 gallons per minute. How long to pump 900 gallons?


18. Comparing Rates

Description:
Determining which rate is faster, cheaper, or more efficient by comparing unit rates.

Explanation:

  • Find the unit rate for each option

  • Compare the unit rates directly

  • Smaller unit cost = better deal; larger unit speed = faster

Example 1:

Store A: 5 pounds for $20 → $4/lb
Store B: 8 pounds for $28 → $3.50/lb
Store B is cheaper.

Example 2:

Car A: 300 miles in 5 hours → 60 mph
Car B: 280 miles in 4 hours → 70 mph
Car B is faster.

Practice Questions (Comparing Rates):

  1. Which is faster: 240 miles in 4 hours or 210 miles in 3 hours?

  2. Which is cheaper: $4.50 for 3 pounds or $7.20 for 6 pounds?

  3. Job A pays $360 for 30 hours. Job B pays $420 for 35 hours. Which pays more per hour?

  4. Which is a better deal: 12 eggs for $3.60 or 18 eggs for $5.40?

  5. Truck A uses 15 gallons for 300 miles. Truck B uses 12 gallons for 270 miles. Which gets better gas mileage (miles per gallon)?


✅ QUIZ 5: Intro to Rates

  1. Find the unit rate: 360 miles in 6 hours.

  2. A gardener plants 24 flowers per hour. How many in 4.5 hours?

  3. Which is faster: 90 meters in 10 seconds or 150 meters in 15 seconds?

  4. A school buys 8 computers for $4,800. What is the unit price?

  5. A train travels 75 miles per hour. How far in 2.8 hours?


UNIT TEST PRACTICE (Cumulative)

  1. Write the ratio 8:14 in simplest form.

  2. Complete:

6


18


30

5

10


20


  1. A recipe uses 3 eggs for 5 cups of flour. How many eggs for 20 cups of flour?

  2. On a map, 1 cm = 8 km. Two towns are 6.5 cm apart. How many km?

  3. Convert 4.5 feet to inches.

  4. Ratio of boys to girls is 5:7. Total students = 48. How many girls?

  5. Plot (2,6), (4,12), (6,18). Are they proportional? What is the constant?

  6. Which is the better buy: 8 oranges for $3.20 or 12 oranges for $4.80?

  7. A car travels 180 miles in 3 hours. What is the unit rate? How far in 5 hours?

  8. A faucet leaks 3 mL per minute. How much in 2 hours (120 minutes)?

Proportional Reasoning with Ratios and Rates

UNIT 1: Proportional Reasoning with Ratios and Rates PART 1: INTRO TO RATIOS 1. Basic Ratios Description: A ratio compares two quantities. I...