Place Value (Ones & Tens)

From the hundred square to columns

In the last lesson you saw that numbers in the same column of the hundred square share the same ones digit: $4$, $14$, $24$, $34$ … That pattern is the first hint of place value: the digit on the right counts single steps (ones); the digit to its left counts whole groups of ten (tens).

For numbers up to $99$ we use two places: tens and ones. The number $37$ means three tens and seven ones — not “three and seven” smooshed together, but $30$ plus $7$.

Same digit, different worth

In $44$, both digits are “$4$,” but they do not mean the same thing. The $4$ on the left is four tens ($40$). The $4$ on the right is four ones ($4$). So $44$ is $40 + 4$.

We write numerals in a fixed order so everyone agrees which digit is counting tens and which is counting ones. Swap the digits in $37$ and you get $73$ — a different number. (When both digits are the same, like $44$, swapping does not change how the number looks — but each $4$ still has a different job: tens vs ones.)

Build the number with blocks

Below, each tall stack is one ten. Each small square is a one. Slide the tens and ones to match a number in your head, then read the chart: the tens digit counts how many stacks, the ones digit counts the loose squares.

When the ones digit is $0$, you only see tens blocks — for example $50$ is five tens and zero ones. When the tens digit is $0$, you are below ten: $6$ is zero tens and six ones (we usually write just “$6$,” but the idea still helps when we extend to larger numbers later).

Try it

Answer in your head or on paper, then open “Show answer” to check.

Repeatable practice

Pool order and exact prompts are randomised each visit. Use “New question (same type)” after a correct answer for a fresh variant.

What is next?

You can split two-digit numbers into tens and ones and see why digit order matters. Next, in lesson 1.1.4, we extend the same idea to hundreds and thousands — same columns, bigger groups.