Tens and ones: what children learn
Place value is the idea that a digit's value depends on where it is in a number. In the two-digit number 47, the 4 is in the tens place and is worth 40, while the 7 is in the ones place and is worth 7. Year 2 pupils learn to recognise the place value of each digit in a two-digit number.
This game asks two kinds of question: 'What is the value of the 4 in 47?' and '47 = ? tens and 7 ones'. Both check that children see a two-digit number as tens and ones, not just two digits side by side. Solid place value is what makes adding, subtracting and comparing bigger numbers possible.
This topic covers the Year 2 statutory requirement in the National Curriculum in England (Number – number and place value): pupils should be taught to “recognise the place value of each digit in a two-digit number (10s, 1s)”. Year 2 pupils are usually aged 6–7.
For families following US standards, the closest Common Core standard is 1.NBT.B.2, which is taught in Grade 1.
How to play
Answer 10 questions before the clock runs out. Tap an answer, or press 1 to 4. Each game has 10 multiple-choice questions and a 100-second timer. A wrong answer shows the correct one before moving on. You earn up to three stars depending on your score.
Step by step
- Make the number with objects. Use bundles of 10 straws, base-10 sticks or 10p coins for tens, and single items or 1p coins for ones. 47 is 4 bundles of ten and 7 single straws.
- Read the digits by place. The left digit tells you how many tens. The right digit tells you how many ones.
- Say the value, not just the digit. The 4 in 47 is worth 40, because it means 4 tens. Saying 'forty' rather than 'four' builds the habit.
- Partition in different ways. 47 = 40 + 7, but also 47 = 30 + 17. Being able to split numbers flexibly helps with subtraction later.
Worked examples
Example 1: What is the value of the 6 in 63?
Working: The 6 is in the tens place, so it means 6 tens.
Answer: 60
Example 2: What is the value of the 8 in 28?
Working: The 8 is in the ones place.
Answer: 8
Example 3: 52 = ? tens and 2 ones
Working: 52 is 50 + 2, and 50 is 5 tens.
Answer: 5
Common mistakes and how to fix them
- Saying the 4 in 47 is worth 4. Ask 'four what?' The answer is four tens, which is 40.
- Muddling teen numbers, such as writing 71 for seventeen. Teen numbers say the ones first. Use a place value chart and build seventeen as 1 ten and 7 ones.
- Thinking 0 means nothing, so 30 is 'just 3'. Show that 0 holds the ones place: 30 is 3 tens and no ones.
Activities to try at home
- Use 10p and 1p coins: make 36p in as few coins as possible.
- Look at house numbers or bus numbers and ask what each digit is worth.
- Swap the digits of a number (47 and 74): which is bigger and why?
Ideas for the classroom
- Use place value charts and arrow cards (40 and 7 overlapping to make 47).
- Play 'make the biggest number' with two digit cards.
- Ask pupils to partition the same number in three different ways.
Printable worksheet
The printable worksheet uses the same question generator as the game, so it practises exactly the same skills. It comes with a separate answer sheet on the second page. Print it, or save it as a PDF from your browser's print menu.
Frequently asked questions
Why does each number in the game use two different digits?
So the question is never ambiguous. In 44, 'the value of the 4' could mean 40 or 4.
Is 'ones' the same as 'units'?
Yes. Older books say units, but the National Curriculum and most schools now say ones.
What comes next?
Year 3 extends place value to hundreds, tens and ones, and Year 4 to thousands.