Loading please wait

The smart way to improve grades

Comprehensive & curriculum aligned

Try an activity or get started for free

Use Estimation to Solve Calculations

In this worksheet, students will use estimation to solve a variety of calculations.

'Use Estimation to Solve Calculations' worksheet

Key stage:  KS 3

Year:  Year 9 Maths worksheets

Curriculum topic:   Number

Curriculum subtopic:   Round/Approximate Numbers Appropriately

Difficulty level:  

Worksheet Overview

In this activity, we will be using our rounding skills to estimate the answers to calculations.

 

This skill is useful for when we need to make approximate calculations for when we don't have a calculator.

 

Engineers use this skill to estimate the  quantity of materials needed for a building.

 

builder looking at a plan

 

We also use rounding when trying to find out what our shopping bill may be as we are going around the supermarket!

 

supermarket trolley

 

Example 1

Round off the values in the calculation to 1 significant figure to work out an estimate to the calculation below.

1.93 + 8.3 + √120

 

First, let's round each value to 1 sig. fig.

1.9 → 2

8.3 → 8

120 → 100

 

Now we have our rounded values we can find an estimate for the calculation.

Remember to apply BIDMAS to your calculations.

 

23 + 8 + √100

= 8 + 8 + 10

= 26

 

Example 2

Round off the values in the calculation to 1 significant figure to work out an estimate to the calculation below.

(2.9 + 8.3)2 ÷ 10.1

 

First, let's round each value to 1 sig. fig.

2.9 → 3

8.3 → 8

10.1 → 10

 

Now we have our rounded values we can find an estimate for the calculation.

 

(3 + 8)2 ÷ 10

= 112 ÷ 10

= 121 ÷ 10

= 12.1

 

Great ... let's try the activity!

What is EdPlace?

We're your National Curriculum aligned online education content provider helping each child succeed in English, maths and science from year 1 to GCSE. With an EdPlace account you’ll be able to track and measure progress, helping each child achieve their best. We build confidence and attainment by personalising each child’s learning at a level that suits them.

Get started
laptop

Try an activity or get started for free

  • National Tutoring Awards 2023 Shortlisted / Parents
    National Tutoring Awards 2023 Shortlisted
  • Private-Tutoring-WINNER-EducationInvestor-Awards / Parents
    Winner - Private Tutoring
  • Bett Awards Finalist / Parents
    Finalist
  • Winner - Best for Home Learning / Parents
    Winner - Best for Home Learning / Parents