Grade 1 · Unit 1: Number and place value

2-digit numbers

Big numbers are made of tens and ones.

Counting in tens

Counting lots of things one by one is slow. It is quicker to make groups of ten. Then we count the tens and the ones left over.

Tens and ones

A long stick is one ten. A small cube is one. Here there are 3 tens and 4 ones. 3 tens and 4 ones make thirty-four, 34.

When you have 10 ones, you can swap them for 1 ten. That is how our numbers work.

Each digit has a place

34 has two digits: 3 and 4. The 3 is in the tens place, so it means 30. The 4 is in the ones place, so it means 4. This is place value.

Same digits, different numbers

43 and 34 use the same digits. But 43 is bigger, because it has 4 tens. The place of a digit changes its value.

What I learnt

• I can make a 2-digit number with tens and ones.
• I know that the tens digit and the ones digit have different values.