Numbers up to 1000
Primary 3 · Mathematics
Numbers up to 1000
Lesson 1 of 3
12 min
Uwase is counting the exercise books in her class store. She counts up to 99 and then she stops. "What comes next?" she asks. "I have run out of numbers."
She has not run out. She has just arrived somewhere new. After 99 comes 100 — one hundred. And the numbers keep going, all the way to 1000.
Today you learn to read those big numbers out loud and write them down, in figures and in words.
When you count in hundreds, you are counting in big jumps. Say these out loud:
100, 200, 300, 400, 500, 600, 700, 800, 900, 1000
In words, they are:
| Figures | Words |
|---|---|
| 100 | one hundred |
| 200 | two hundred |
| 300 | three hundred |
| 500 | five hundred |
| 900 | nine hundred |
| 1000 | one thousand |
Look carefully at 1000. It has four digits: a 1 and then three zeros. It is the biggest number in this unit, and the only one with four digits.
Take the number 247.
Step 1 Look at the first digit. It is 2. That is the hundreds digit, so you begin with two hundred.
Step 2 Now cover the 2 with your finger. What is left? 47. You already know that number: forty-seven.
Step 3 Join the two parts with the little word and.
247 = two hundred and forty-seven.
That is the whole trick. Read the hundreds digit, cover it, then read what is left.
Example: 630
First digit is 6, so: six hundred. Cover the 6 and you are left with 30, which is thirty.
630 = six hundred and thirty.
Example: 805
First digit is 8, so: eight hundred. Cover the 8 and you are left with 05, which is just five. The zero is not read out loud — it is only holding an empty seat.
805 = eight hundred and five.
Now somebody says a number and you must write it.
"Five hundred and twelve"
The hundreds part is 5. The rest is twelve, which is 12. Put them side by side: 512.
"Nine hundred and six"
The hundreds part is 9. The rest is six, which is 6. But careful — a three-digit number needs three digits. Between the 9 and the 6 you must put a 0 to hold the tens seat.
Nine hundred and six = 906. Not 96. Not 9006.
Counting on means going forward by one each time. Counting back means going backwards by one each time.
Count on from 396: 396, 397, 398, 399, 400
After 399 the ones are full and the tens are full, so the whole number rolls over to a fresh hundred: 400. It is exactly like 9 rolling to 10, only bigger.
Count back from 802: 802, 801, 800, 799
Going backwards past 800 lands you on 799. That surprises many children, so say it twice.
You can also count on in tens: 460, 470, 480, 490, 500.
And in hundreds: 250, 350, 450, 550. Only the hundreds digit changes; the rest of the number stays asleep.
Tip
The finger trick. To read any three-digit number, put your finger over the first digit. Read the two digits that are left — you already learned those last year. Then take your finger away and say the hundreds first, with and in the middle.
734 → cover the 7 → you see 34 → "seven hundred and thirty-four".
Do each one on paper first, then tap Show answer to check.
Write 583 in words.
Answer: Cover the 5, you see 83 (eighty-three). So 583 is five hundred and eighty-three.
Write "seven hundred and nine" in figures.
Answer: Hundreds digit is 7. "Nine" is 9 ones. There are no tens, so a 0 holds that seat: 709.
Count on: 498, 499, ___, ___
Answer: 500, 501. After 499 the number rolls over into a new hundred.
Count back in tens from 320: 320, ___, ___, ___
Answer: 310, 300, 290. Only the tens change, until you drop below 300.
Mugisha writes one thousand as 100. Is he right?
Answer: No. He wrote one hundred. One thousand is 1000 — a 1 followed by three zeros.
What you learned today
Quick check
How do you read 805?
