If you are given a fact, use it: multiplication
The Short Answer
By Year 5 your child can multiply. What the 11+ tests is whether they notice when the paper has already done the work: if you are told 75 × 462 = 34 650, then 7.5 × 462 is ten times smaller, so the answer is 3 465 with no multiplying at all. Scaling the given fact places the decimal point exactly, and an estimate made first is the check on it.
What do multiplication questions test at this level?
By Year 5 your child can already do the arithmetic. So the paper is not really testing whether they can multiply — it is testing two other things.
Whether they notice a fact the question has already given them, and whether they know where the decimal point goes.
If you are given a fact, use it
This is worth real marks and it is easy to miss.
The paper tells you: 75 × 462 = 34 650.
Then it asks for 7.5 × 462.
Here is how to think about it. 7.5 is ten times smaller than 75. Nothing else has changed. So the answer must be ten times smaller as well: 34 650 ÷ 10 = 3 465.
No multiplying at all.
Four moves are worth knowing:
| If one number… | the answer… |
|---|---|
| doubles | doubles |
| halves | halves |
| becomes ten times smaller | becomes ten times smaller |
| becomes ten times larger | becomes ten times larger |
The scaling, drawn.
The routine
Read it twice. This is where a supplied fact gets noticed.
Multiply or share? Decide before touching the numbers.
Estimate. Two seconds, and it tells you the size of the answer.
Pick your method — long multiplication, grid, or scaling from a given fact.
Check it back against the estimate.
Most of the time should go on steps one and three. The calculating is the quick part.
Why the estimate checks the point
This is the argument worth making to a child who thinks estimating is a waste of time.
75 × 462 = 34 650. 7.5 × 462 = 3 465. 0.75 × 462 = 346.5.
The same run of digits each time, with the point in a different place. Place value says exactly where it goes — make one number ten times smaller and the answer is ten times smaller. The estimate is the check that you put it there. With about 3 500 in mind, 34 650 and 346.5 are plainly wrong. On a decimal question that check is worth making every time.
Where do pupils lose marks?
Doing the work the paper had already done, and running short of time later.
Getting the digits right and the size wrong — 346.5 instead of 3 465.
Choosing a method by habit rather than by what the numbers invite.
Try it yourself
Look for a fact you have been given before you start calculating. Estimate before you commit.
- You are told 75 × 462 = 34 650. What is 7.5 × 462?
- Using the same fact, what is 150 × 462?
- Estimate 7.5 × 462 before answering. What should it be near?
- Why does the estimate matter more on a decimal question than on a whole-number one?
- A box holds 24 pencils. How many in 35 boxes?
- 3 465. 7.5 is ten times smaller than 75, and nothing else has changed, so the answer is ten times smaller too: 34 650 ÷ 10. No multiplying at all.
- 69 300. 150 is double 75, so the answer doubles: 34 650 × 2.
- About 3 500. Round to 7.5 × 460, or more roughly 8 × 450. That is enough to tell you the answer is thousands rather than hundreds or tens of thousands.
- Because a slip with the decimal point changes the size of the answer by ten times or more. 75 × 462 = 34 650, 7.5 × 462 = 3 465 and 0.75 × 462 = 346.5 share the same run of digits apart from the final zero, so a misplaced point is easy to miss by looking at the digits and obvious against an estimate of about 3 500.
- 840. There is no given fact here, so this is a straightforward long multiplication — but estimate first: 24 × 35 is roughly 25 × 35, which is about 875, so 840 is plausible and 84 or 8 400 would not be.
How much practice does this type need at home?
Two things, neither of them long multiplication.
Scaling. Say a fact — 8 × 45 = 360 — then ask for 16 × 45, 4 × 45, 0.8 × 45. Ten seconds each, and the fourth one teaches more about decimals than a page of them.
Estimating. Give a calculation and ask only for the rough size. A child who reliably knows whether an answer should be in the hundreds or the thousands has removed most of the ways this topic goes wrong.
Free: a Maths workbook
Questions across the Maths question types, with the method printed at the top and full answers at the back. One workbook for the whole strand, not a sheet per question type.
Frequently Asked Questions
What are the scaling moves worth knowing?
Four. If one number doubles, the answer doubles. If one number halves, the answer halves. If one number becomes ten times smaller, so does the answer. And if one number becomes ten times larger, so does the answer. That is the whole toolkit, and it turns questions that look like two minutes of long multiplication into ten seconds of thinking.
How does my child spot that a fact has been given?
By reading the question twice, which is the first rung of the routine for exactly this reason. A supplied fact usually sits in the stem — 'You are told that…' — or in the previous part of the same question. Children who start calculating on the first read do the work the paper was trying to save them, and then run short of time later.
Why estimate if the calculation is going to be exact anyway?
Because it is the quickest check on the size of the answer. Place value decides where the point goes: 7.5 is a tenth of 75, so 7.5 × 462 is a tenth of 34 650, which is 3 465. But 34 650, 3 465 and 346.5 look alike at a glance, and a slip with the point is easy to make. An estimate of about 3 500, made first, shows straight away which one is right.
Should my child use long multiplication or the grid method?
Whichever they are reliable with. Speed matters less than accuracy at this stage, and a child who is confident with the grid method and shaky with long multiplication should use the grid. What we would insist on is that they choose deliberately rather than defaulting, which is why choosing a method is its own rung in the routine.
Sources
- GL Assessment — 11+ familiarisation materials and question type descriptions Published 2025.
- Clever Clogs Academy — our own Year 4 and Year 5 lesson records, Winslow Published September 2025 to July 2026.
We are not affiliated with, endorsed by or connected to GL Assessment or Buckinghamshire Council. Test arrangements change; always check the council's own pages for the current year's dates.
We Teach This Method Every Week in Winslow
Groups of no more than six pupils with two qualified teachers, in person or online. Come and see a session before you decide.