Rounding and estimation – Year 7 maths lesson
Lesson 3 of 18 in the Year 7 maths course
UK version. UK school years, UK spelling and pounds (£). · US Math Department
A complete 45-minute lesson for Year 7 (ages 11–12) that runs on this page – at school or at home. Every answer is marked straight away, with a worked explanation.
- Time
- 45 minutes + 20 min homework
- Year
- Year 7 (ages 11–12)
- You need
- Paper, a pencil and this page
- Marked
- Instantly, with explanations
For parents: how to use this lesson
You don't need to know this topic yourself. The lesson explains each step on screen, one tidy step at a time. Every answer is marked straight away with a worked explanation, so you never have to mark anything.
- Read what your child will learn and the big ideas together.
- Press Start the lesson below and sit with your child for the teaching and the worked examples (about 19 minutes).
- Let them do the practice on their own. They choose Getting started, On track or Challenge – start on On track and move up after a few right in a row.
- Finish with the exit ticket and the talk question: “Why must 3,842 to 1 significant figure be 4,000 and not 4?”
- Later that day or the next day: the homework (20 minutes), then a practice test.
Watch out for
- Counting leading zeros as significant figures (0.0372 to 2 s.f. as 0.03). Start counting at the first non-zero digit: 0.037.
- Dropping place-holder zeros (3,842 to 1 s.f. as 4). The answer must be about the same size: 4,000.
Tip for home: Estimate a shopping total by rounding each price.
What your child will learn
We are learning to round to decimal places and significant figures and estimate answers.
Success looks like
- I can round to decimal places.
- I can round to significant figures.
- I can estimate to check answers.
Key words
- decimal place
- a place after the decimal point
- significant figure
- a digit that shows the size of a number, counted from the first non-zero digit
- estimate
- a rough answer using rounded numbers
- approximately
- roughly (≈)
What to have ready
- Paper and a pencil
- This page on a computer, tablet or phone
- For the hands-on part: Estimate the answers to some calculator sums before pressing equals, then compare.
The big ideas (for the adult)
To round to decimal places, count places after the point; to round to significant figures, count from the first non-zero digit.
Look at the next digit: 5 or more rounds up, 4 or less rounds down. Keep zeros as place holders: 3,842 to 1 significant figure is 4,000.
To estimate, round every number to 1 significant figure and calculate. Use it to check a calculator answer.
The lesson, step by step
| Part | Time | How it is checked |
|---|---|---|
| Starter: quick recall | 5 min | Marked by Classfern |
| Teaching input | 10 min | Not assessed, self-checked |
| Worked examples and guided practice | 9 min | Not assessed, marked by Classfern |
| Independent practice | 15 min | Marked by Classfern |
| Plenary and exit ticket | 6 min | Marked by Classfern, self-checked |
Starter, "your turn", practice and exit ticket are marked by Classfern. Worked examples and teaching are not assessed. The hands-on task and the reflection are self-assessed. Explanations in talk are judged by the parent and not recorded.
The lesson
It runs here on the page. No sign-up and no names – progress is kept only in this browser.
Homework and practice at home
20 minutes: 10 practice questions, 3 multiple-choice questions and 2 to remember from earlier work, then a short reflection. New questions every time, all marked instantly.
More practice
More Year 7 maths lessons
- Ordering numbers, decimals and negatives
- Calculating with negative numbers
- Powers and roots
- Written methods with decimals
- Calculating with fractions
- Fractions, decimals and recurring decimals
- Quadrilaterals and symmetry
- 3-D shapes, plans and elevations
- Pie charts and time series graphs
- Probability
- Algebraic notation
- Simplifying expressions
- Solving linear equations
- Sequences and the nth term
- Ratio
- One quantity as a fraction or percentage of another
- Scale drawings and maps
Curriculum
National Curriculum for England, Year 7: “round numbers and measures to an appropriate degree of accuracy [for example, to a number of decimal places or significant figures]”
National Curriculum for England, Year 7: “use a calculator and other technologies to calculate results accurately and then interpret them appropriately”
Contains public sector information licensed under the Open Government Licence v3.0.
Our lessons and questions are our own. They are not written or endorsed by any government department, testing agency or exam board.