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Checking by Estimating: Free Printable Worksheet for Year 5
- ForYear 5
- StageKey Stage 2
- CostFree
- FormatPrintable PDF
Checking by Estimating is a free printable maths worksheet for Year 5 (ages 9 to 10). Each question shows a calculation with an answer already written. Children round the numbers, do an easy sum and decide whether the answer is sensible. Page 2 gives the grown-up notes, help ideas, a stretch task and the answers.
It comes from the Mini Minds Hub, the free library of printables from Jaques of London, the British games and toy company that has been making games for families since 1795. Print both pages, give page 1 to your child and keep page 2 for yourself. Black and white printing works well.
What is on the sheet
Each numbered question shows a calculation with an answer already written, and there is space to respond. Children do not work out the exact answer first. They round the numbers, do the easy sum in their head or on paper, and compare the result with the written answer. The sheet uses addition, subtraction and multiplication, with numbers up to about a thousand.
- 49 + 52 = 201
- 398 + 205 = 603
- 81 - 39 = 62
- 7 × 49 = 343
- 603 - 198 = 805
- 19 × 5 = 195
- 312 + 689 = 1,001
- 52 × 4 = 208
Spot the wrong answer
Is 6 × 29 = 274 sensible?
This question is not on the sheet. It shows two ways to use an estimate.
Method 1: round and compare- Round 29 up to 30, because it is close and easy to multiply.
- Do the easy sum: 6 × 30 = 180.
- Compare 274 with 180. The written answer is far bigger than the estimate, so it is probably wrong.
- 29 is 1 less than 30, so 6 lots of 29 is 6 less than 6 lots of 30.
- Start with the estimate of 180 and take away 6.
- 180 minus 6 is 174, which is close to the estimate and shows the right answer.
Estimating habits to build
Round first
Look at each number and choose a friendly number nearby, such as the nearest ten or the nearest hundred. Write the rounded numbers down before doing anything else.
Say the easy sum
Do the sum with the rounded numbers. Say it aloud: the sound of a simple sum helps children notice when something is off.
Compare, then decide
Ask whether the written answer is close to the estimate. If it is far too big or too small, mark it as suspicious and look again.
Check the operation
Sometimes an answer is wrong because the wrong sign was used. Ask whether the answer should be bigger or smaller than the numbers in the question.
Why estimate before trusting an answer?
An estimate is an answer that is close enough, found by using easier numbers. Adults do it all the time. We guess whether a basket of shopping will fit a budget, or whether a journey will take long enough to leave early. Children who estimate learn to ask, "Is this roughly the size I expected?" before they accept a number.
Checking by estimating does not prove an answer is exactly right. What it does well is catch big slips, such as a missing digit, a digit in the wrong place, or the wrong operation. Answers that pass the estimate test can still be slightly out, so other checks, such as working backwards, are useful too.
Skills and curriculum link
- Estimating
- Rounding
- Checking answers
- Mental addition and subtraction
- Multiplying by rounded numbers
- Reasoning about size
This sheet supports the area below. It is matched to the published England framework. Please check it against your own school plan.
| Framework | Subject or area | Strand | Year |
|---|---|---|---|
| National Curriculum (England) | Maths | Addition and subtraction | Year 5 |
What children will be able to do
- I can round numbers to estimate an answer.
- I can use my estimate to check if an answer is sensible.
- I can spot an answer that is too big or too small.
Helpful ideas for estimating
- Rounding to the nearest tenLook at the ones digit. If it is 5 or more, round up to the next ten. If it is less than 5, stay on the ten below.
- Rounding to the nearest hundredLook at the tens digit in the same way. It tells you whether to go up to the next hundred or stay put.
- Choose a helpful placeRound to the place that gives you a sum you can do easily. Larger numbers often suit the nearest hundred.
- Close, not equalAn estimate is not meant to match the exact answer. A sensible written answer should be near it, and a wrong one is often far away.
Key words
- EstimateAn answer that is close to the exact one, found by using easier numbers.
- RoundChange a number to a nearby, simpler one, such as the nearest ten or hundred.
- SensibleAn answer that makes sense and is about the size you would expect.
- SumThe answer to an addition.
- DifferenceThe answer to a subtraction.
- ProductThe answer to a multiplication.
How to use it
- Print both pages. Page 1 is for your child. Keep page 2, which has the notes and answers.
- Read the first question together. Point out that the answer is already written and the job is to decide if it is sensible.
- Ask your child to round each number first, then do the easy sum and compare it with the written answer.
- Let them decide which answers look wrong. Ask, "How do you know?" Listen for words such as bigger, smaller and close.
- Check with page 2. Come back on another day and try the tricky ones again. Repeating a familiar sheet builds confidence.
Help, stretch and game ideas
If it feels too hard
Start with the addition questions and use a number line. Round each number to the nearest ten, then add the rounded numbers and say the easy sum aloud. Ask, "Is the written answer close to my estimate?" Move on to the other signs once that feels steady.
To stretch confident children
For each wrong answer, work out the right one. Then write three calculations of your own and make one answer wrong on purpose. Swap with a friend and see if they can spot it using only rounding and an estimate.
Make it a game
Play Estimate Detective. Write six calculations with answers on paper and make some answers wrong. Swap with a partner, who rounds, estimates and points to the wrong ones. Or check a shopping list total by rounding each price to the nearest pound.
Mistakes to watch for
Watch forA child works out the exact answer and does not round at all.
Try thisCover the numbers with rounded ones first. Ask them to write the rounded sum before they do anything else.
Watch forA child says an answer is wrong because it does not match the estimate exactly.
Try thisExplain that an estimate is close, not equal. Ask, "Is it near my estimate or far away?"
Watch forA child rounds to a place that leaves a hard sum.
Try thisTry again with a different place. Choose the nearest ten or hundred, whichever gives a sum you can do quickly in your head.
Talk about it
- How did you round the numbers to make an estimate?
- Why is an estimate useful if it is not the exact answer?
- How would you know if an answer was too big?
- When might you estimate in real life?
- Did rounding up or rounding down make the sum easier here?
- Can an answer be close to the estimate and still be wrong? How could you check?
Take it off the page
Shop price check
Look at a few prices in a catalogue or on a shelf. Round each to the nearest pound and estimate the total before an adult adds the exact amount.
Journey estimates
Pick three journeys you often make. Estimate the distance or time by rounding, then compare with a map or a clock.
Wrong on purpose
Write five calculations on cards with answers. Make some wrong. Ask a family member to find them by estimating.
Who it is for
Parents
Sit beside your child for the first question, then let them lead. Praise the thinking, not only the right answers. If they get stuck, ask them to round the numbers and say the easy sum aloud.
Teachers
Use it as a starter, a plenary, an early finisher task or a table activity. It needs no preparation beyond printing. Page 2 gives support and stretch ideas for mixed ability groups, and the questions work well for reasoning talk.
Home educators
Print it as part of a wider maths plan. It pairs well with real shopping, cooking measures and journeys. You can print it again for brothers and sisters, or for revision a few weeks later.
Where this skill fits
Before this, children need to round numbers to the nearest ten and hundred, and to add, subtract and multiply with confidence. Fact family work and number line practice also help them see how numbers relate.
After this, children use estimating to check answers in longer calculations and in problems with money and measures. It is a habit that stays useful as the numbers get bigger and the sums get harder.
Check it worked
Ask these when the sheet is finished. Listen for the reasoning, not just the answer.
- How did you round the numbers to make an estimate?
- How close is your estimate to the exact answer?
- How would you know if an answer was wrong?
Questions parents and teachers ask
- What age is Checking by Estimating for?
It is written for Year 5 (ages 9 to 10), in Key Stage 2. Children in nearby years can try it too, with more support for younger ones or the stretch task for confident learners.
- What do children actually do on the sheet?
They look at calculations with answers already written. They round the numbers, do an easy sum and compare it with the written answer to decide whether it is sensible.
- Do children need to find the exact answer?
No. The main job is to estimate and compare. The stretch task asks children to work out the right answer for the ones they think are wrong, and page 2 has the answers.
- What if my child finds it hard?
Start with the addition questions and use a number line. Round to the nearest ten, say the easy sum aloud and compare. Go back to the rest later when it feels more comfortable.
- Is this a screen free activity?
Yes. It needs only paper and a pencil. It works well for quiet time after school, a rainy day or a calm moment at the weekend, and it gets children talking about their thinking.
- Can teachers use it in class?
Yes. It works as a starter, plenary, early finisher task, homework or table activity. It needs no preparation beyond printing, and page 2 has help and stretch ideas for mixed ability groups.
- Is it free and do I need colour printing?
It is free to print for home and classroom use. Black and white on plain A4 paper works well, so no colour printing is needed. You can print it again for revision.
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Made by Jaques of London, making games for families since 1795. A printable supports classroom learning and does not replace a teacher.