Numbers up to 50
Primary 1 · Mathematics
Numbers up to 50
Lesson 4 of 6
12 min
Let's begin
Uwase helps her mother pack beans at home.
They put ten beans in each small bag. The rest stay loose on the mat.
Her mother asks, “How many beans in all?” Today you will answer that fast.
Look at the number 34.
The first digit is 3. It means 3 bundles of ten.
The second digit is 4. It means 4 loose ones.
Say it like this: three tens and four ones.
Careful! Never say “a three and a four”. The 3 is not three beans. It is three whole bundles.
Read every row of this table out loud.
| Number | Tens | Ones |
|---|---|---|
| 18 | 1 | 8 |
| 26 | 2 | 6 |
| 34 | 3 | 4 |
| 40 | 4 | 0 |
| 50 | 5 | 0 |
Worked example
4 tens and 7 ones.
Step 1 Put out 4 bundles. Count them: 10, 20, 30, 40.
Step 2 Lay 7 loose beans beside the bundles.
Step 3 Count on from 40: 41, 42, 43, 44, 45, 46, 47.
4 tens and 7 ones make 47.
34 is 3 tens and 4 ones.
43 is 4 tens and 3 ones.
They use the same two digits. They are not the same number.
Careful! Do not add the digits. 3 and 4 make 7, but 34 is far more than 7.
40 is 4 bundles. Nothing is left loose.
We write a 0 in the ones place.
The 0 holds the place open. Without it you would write 4, and 4 is only four beans.
Tip
Left digit is bundles. Right digit is loose
Point at the left digit and say “bundles”. Point at the right digit and say “loose ones”.
Do this with any number you meet, at home or on the road.
Watch bundles and loose ones up to 50.
Do each one, then tap Show answer to check.
27 is ___ tens and ___ ones.
Answer: 2 tens and 7 ones. The 2 is bundles, the 7 is loose.
3 tens and 9 ones make which number?
Answer: 39. Write the 3 first, then the 9.
How many tens are in 50?
Answer: 5. Count the bundles: 10, 20, 30, 40, 50.
In 45, which digit shows the bundles?
Answer: the 4. It stands on the left.
Byiringiro fills 5 bags of ten bottle caps. None are loose. How many caps?
Answer: 50. Five tens and 0 ones.
What you learned today
Quick check
How many tens are in 36?
