Class 07 To solve a puzzle of linear equations in one variable by activity method

 ACTIVITY – Linear Equations in one Variable

Objective : 

To solve a puzzle of linear equations in one variable by activity method.

Materials Required :  

Calendar of any year. 

Procedure:

Choose four dates mentally to form a box as shown 

in the table below:

2. Find the sum of the chosen dates. Here, the sum of four chosen dates is 72. Divide 72 by 4 to get 18.

3. Now subtract 4 from 18 to get the first date, i.e., 14. To obtain other dates add 1, 7 and 8 respectively to 14.

Therefore, desired dates are 14, 15, 21 and 22.

Note: 1. This activity is done with the help of a friend.

2. Your friend would tell only the sum of the four dates.

3. After finding the dates, ask the friend whether the answer is correct or not.

Mathematical Explanation:

Let the first number (date) be x.

Then the next numbers would be x + 1, x + 7 and x + 8.

 x + x + 1 + x + 7 + x + 8 = 4x + 16

Let us say that the sum of four dates = 72

4x + 16 = 72

4 (x + 4) = 72

x + 4 = 18

x = 14

That gives you the first date. The other dates are 15, 21 and 22.