Forming Equations – Find the Number

Table of Contents

• Forming Equations – Find the Numbers
  • Example 1
  • Example 2
• Summary
• What’s Next?

In the previous segment of the chapter ‘Simple Equations,’ we looked at Forming equations.

In this segment, we will learn how to find numbers.

How to form equations to find numbers?

Let us understand how to form equations to find numbers with the help of the following two examples:

Example 1

12 subtracted from a number gives us 8. Find that number.

Step 1: Break the word problem into parts to form the equation.

• 12 subtracted – This means that 12 is subtracted from something.
• From a number – The number is not given. This is the number that we need to find. We will assign a variable to that number x
• Gives us 8 – This means that when 12 is subtracted from x we get 8.
• Form the equation – From the above deductions, we can arrive at the equation.

That is,

x – 12 = 8

Step 2: Solve the equation

∴ ? = 12 + 8

∴ ? = 20

Example 2

Find a number that is 3 times the sum of 5 and 7.