🧱 Hundreds, Tens and Ones: Three-Digit Numbers

Hello! Today we are going to work in the block factory. We will use little blocks to build, read and compare big 3-digit numbers.

Let’s start with little cubes. One cube is one one. If we stick 10 ones together, we get a rod. We call this rod a ten: 10 ones make 1 ten.

Now let’s put 10 rods side by side. It makes a big square! We call this a hundred: 10 tens make 1 hundred. A hundred has 100 small squares, so it is 100 ones.

Let’s build a number: 3 hundreds, 4 tens and 7 ones. Each digit sits in its own column. Together they make 347. We say: three hundred and forty-seven.

In the number 347, every digit shows two things. There is the digit itself: 3, 4 and 7. And there is its value in its place, which is called place value: 3 hundreds is 300, 4 tens is 40, and 7 ones is 7.

In the number 305 there are no tens. The tens column stays empty, so we write a 0 there. Zero holds the empty place. Without it we would have 35: 3 tens and 5 ones, a much smaller number!

When we compare two numbers, we start from the left. 436 and 452: the hundreds are the same, 4 and 4. Then we look at the tens: 3 is less than 5. So 436 is less than 452.

If the hundreds are different, we can decide straight away. 623 and 598: 6 hundreds is more than 5 hundreds. We do not need to look at the tens or the ones. 623 is greater than 598.

10 ones make 1 ten, and 10 tens make 1 hundred. In a three-digit number each digit is in its own place, we write 0 in an empty place, and we compare numbers from the left. Now try it in Block Factory!