Year 3 maths · Key Stage 2 · Number – number and place value

Year 3 place value: hundreds, tens and ones explained

Place value is the idea that a digit is worth a different amount depending on where it sits in a number. In Year 3 children work with numbers up to 1,000: they learn what each digit in a three-digit number is worth, read and write these numbers in numerals and words, compare and order them, and find 10 or 100 more or less than any number.

Place value to 1,000, explained

In the number 346, the 3 is worth 3 hundreds (300), the 4 is worth 4 tens (40) and the 6 is worth 6 ones. Schools say “ones” rather than “units”. Children use objects such as base 10 blocks, place value counters and charts with H, T and O columns so they can see that ten ones make one ten and ten tens make one hundred.

Splitting a number into parts like this is called partitioning. Children first learn 146 = 100 + 40 + 6, then that the same number can be split in other ways, such as 130 + 16 or 100 + 30 + 16. This flexibility matters: it’s what makes mental addition work and what children use when they exchange in column subtraction later on.

Zero has an important job. In 305 it shows there are no tens, holding the other digits in their places. Without it, the number would be 35. Many of the trickiest Year 3 questions involve zeros or crossing a hundred, such as 10 more than 395.

Children also compare and order numbers to 1,000 using the signs < and >, place numbers on a number line, and count from 0 in 4s, 8s, 50s and 100s. Counting in 50s and 100s links naturally to money and to measuring in grams and millilitres.

Words your child will hear

Digit: One of the symbols 0 to 9 used to write numbers. 346 has three digits.
Place value: What a digit is worth because of its position: hundreds, tens or ones.
Partition: Split a number into parts, such as 346 = 300 + 40 + 6.
Placeholder: A zero that keeps the other digits in the right places, as in 305.
Exchange: Swap 10 ones for 1 ten, or 10 tens for 1 hundred (and back).
Estimate: A sensible guess, such as placing 720 roughly on a 0 to 1,000 number line.
< and >: “Is less than” and “is greater than”. 289 < 301.

What the National Curriculum says

In Year 3, pupils should be taught to:

Count from 0 in multiples of 4, 8, 50 and 100; find 10 or 100 more or less than a given number
Recognise the place value of each digit in a 3-digit number (100s, 10s, 1s)
Compare and order numbers up to 1,000
Identify, represent and estimate numbers using different representations
Read and write numbers up to 1,000 in numerals and in words
Solve number problems and practical problems involving these ideas

Objectives from the National Curriculum in England, © Crown copyright, used under the Open Government Licence v3.0.

A worked example

What is 10 more than 395?

Partition 395 into hundreds, tens and ones: 3 hundreds, 9 tens and 5 ones.
```
      H   T   O
      3   9   5
```
10 more means one more ten. The tens go from 9 to 10.
A column can only hold up to 9, so exchange the 10 tens for 1 hundred. That leaves 0 tens and makes 4 hundreds. The ones don’t change.
```
      H   T   O
      3   9   5
 +10     +1
      3  10   5   10 tens = 1 hundred
      4   0   5
```

10 more than 395 is 405.

Common mistakes and how to help

Writing “three hundred and four” as 3004 or 34

Children write what they hear, “three hundred” as 300 and then “four”, giving 3004. Others drop the zero altogether, because there are no tens to say out loud.

What helps: Use a place value chart with H, T and O columns. Every three-digit number fills all three columns, so a zero goes in the tens when there aren’t any.

Getting stuck when counting crosses a hundred

Asked for 10 more than 395, a child may say 3105 (writing 10 in the tens column) or 305 (forgetting the exchange).

What helps: Count in tens out loud across the boundary: 375, 385, 395, 405. Then show it with coins or blocks: ten 10p coins swap for a pound.

Comparing numbers by their digits rather than their places

Seeing the 8 and 9 in 89, a child decides 89 is bigger than 102 because those digits are bigger than 1, 0 and 2.

What helps: Compare the hundreds first. 102 has 1 hundred and 89 has none, so 102 is bigger, whatever the other digits are.

Thinking a number can only be partitioned one way

Lots of practice with 146 = 100 + 40 + 6 can make it seem like the only right answer.

What helps: Make 146 with coins in as many ways as you can: £1, four 10p and six 1p, or thirteen 10p and sixteen 1p. Each one is correct.

How to help at home

Count with coins. £1 coins, 10p and 1p coins are a ready-made place value set. Lay out £3, 4 tens and 6 pennies and ask how much it is in pence (346p).
Read numbers out and about. Bus routes, door numbers, page numbers and prices are all three-digit practice. Ask what the middle digit is worth.
Play “guess my number”. Think of a number below 1,000 and give clues: “It’s between 300 and 400. It has 7 tens. Its ones digit is even.” Then swap roles.
Make the biggest and smallest number. Roll three dice or draw three digit cards. What’s the largest number you can make? The smallest? How far apart are they?

Builds on

Year 2: Tens, ones and counting in steps

Leads on to

Year 4: Thousands and negative numbers
Year 4: Rounding and Roman numerals

Everything in Year 3 maths

Updated 20 October 2026.