What to notice
Every starting number ends in 0, which is the test for dividing by 10 with nothing left over. A number ending in any other digit, like 34, leaves a remainder: 3 tens and 4 ones.
The answers count up by one as the starting numbers go up by ten, from 10 to 120. 110 ÷ 10 = 11 and 120 ÷ 10 = 12 are the same idea with three-digit numbers: 12 tens is 120.
Dividing by 10 and by 5 are linked: the answer for 5 is double the answer for 10. 60 ÷ 10 = 6 and 60 ÷ 5 = 12.
Thinking in tens also explains why 120 ÷ 10 = 12 needs no new rule. A place-value chart with hundreds, tens and ones columns shows 120 as 1 hundred and 2 tens, and 1 hundred is 10 tens, so there are 12 tens in all. A child who can say that has understood something bigger than this one table.
How to practise at home
- Use dimes: 80 cents is how many dimes? That is 80 ÷ 10.
- Bundle straws or craft sticks into tens with rubber bands. Bundle 50 and count the bundles.
- Ask “how many tens in…?” for numbers past 120 too, like 200 or 350. It builds confidence with bigger numbers.
- The drill on this page is quick; use it as a warm-up before a harder division table.
- Play a quick guessing game in the car: you say a multiple of ten up to 120, your child says how many tens. Then swap roles and let your child try to catch you out.
Slips to watch for
- Taking off too many zeros, and answering 1 for 100 ÷ 10. Ask how many tens make 100: ten.
- Mixing up dividing and multiplying by 10, and answering 700 for 70 ÷ 10. Read the sign aloud first.
- Answering 0 for 10 ÷ 10. A number divided by itself is 1.
- Dropping the zero from the 10 instead of from the starting number, reading 60 ÷ 10 as if it were 60 ÷ 1 and answering 60. Point at each number as you read the fact aloud.