Tens and Ones

Counting lots of things one by one takes a long time, and it is easy to lose count. Clever counters put things into groups of ten. Today you will learn about tens and ones, the secret code inside every two-digit number.

Making groups of ten

If you have a big pile of blocks, make towers of 10. Then count the towers by tens and the leftover blocks by ones.

Example

Aisha has a pile of building blocks. She makes 3 towers of 10, and has 4 blocks left over. She counts: “ten, twenty, thirty… thirty-one, thirty-two, thirty-three, thirty-four.” She has 34 blocks.

What the digits mean

A two-digit number has two digits. The left digit tells how many tens. The right digit tells how many ones.

Zero holds the place

In 70, the 0 means there are no extra ones. We still write the 0 so the 7 stays in the tens place. Without it, 70 would just be 7!

Drawing tens and ones

You can draw numbers quickly using sticks and dots:

• Draw a long line (a stick) for each ten.
• Draw a small dot for each one.

So 25 is 2 sticks and 5 dots. 41 is 4 sticks and 1 dot.

Same digits, different numbers

Look at 23 and 32. They use the same digits, but they are different! 23 is 2 tens and 3 ones. 32 is 3 tens and 2 ones. The place of a digit changes its value.

Key takeaways

• Grouping things in tens makes counting faster.
• In a two-digit number, the left digit shows tens and the right digit shows ones.
• Zero holds the ones place in numbers like 40 and 70.
• Where a digit sits changes what it is worth.

Practice

How many tens and ones are in each number? 46, 81, 60. Then draw 27 with sticks and dots.

Answers: 46 is 4 tens and 6 ones, 81 is 8 tens and 1 one, 60 is 6 tens and 0 ones. 27 is 2 sticks and 7 dots.