Class 07 Activity - Decimals To find the product of two decimals using a squared paper by shading the squares.

 Activity - Decimals

Objective :  

To find the product of two decimals using a squared paper by shading the squares.

Materials Required: 

Squared papers, Colour pencils, geometry box, etc.,

Procedure : 

I. To represent 0.3 x 0.7

Take a 10 x 10 squared grid, colour its 3 rows red as shown below

2. On the same grid colour 7 columns green as shown below.

II To represent 0.5 x 0.5

1. Take a 10 x 10 square grid. Colour its 5 rows red and 5 columns green as shown below.

III To represent 0.8 x 0.6

1. Take a 10 x 10 square grid. Colour its 8 rows red and 6 columns green as shown below.

Observations:

A 10 x 10 square grid  has 100 squares.

So, 1 square represents ¹/₁₀₀ = 0.01 & 10 square represents ¹⁰/₁₀₀ = 0.1

Or 1 row or 1 column of the grid represents 0.1

2. In figure 2 , the 3 rows (coloured red) represent ³⁰/₁₀₀ = 0.3

And, the 7 columns ( coloured green ) represent ⁷⁰/100 = 0.7

So the double coloured portion represents 0.3 x 0.7

The double coloured portion contains 21 squares, so it represents ²¹/₁₀₀ = 0.21

Hence, 0.3 x 0.7 = 0.21

3. In figure 3, the 5 rows (coloured red) represent ⁵⁰/₁₀₀ = 0.5

And the 5 columns (coloured green) represent ⁵⁰/₁₀₀ = 0.5

So the double coloured portion represents 0.5 x 0.5.

The double coloured portion contains 25 squares, so it represents ²⁵/₁₀₀ = 0.25

Hence, 0.5 x 0.5 = 0.25

Observations:

4. In figure 4 , the 8 rows (coloured red) represent ⁸⁰/₁₀₀ = 0.8

And, the 6 columns ( coloured green ) represent ⁶⁰/₁₀₀ = 0.6

So the double coloured portion represents 0.8 x 0.6

The double coloured portion contains 48 squares, so it represents ⁴⁸/₁₀₀ = 0.48

Hence, 0.8 x 0.6 = 0.48

Do yourself:

0.2 x 0.9

2. 0.8 x 0.3

3. 0.5 x 0.7

4. 0.4 x 0.4 

5. 0.6 x 0.9

6. 0.1 x 0.9