Basic 2 · Mathematics · Counting, Representation and Cardinality
Numbers up to 1000
In this topic you will read, write and count numbers up to 1000 using hundreds, tens and ones.
By the end of these notes you should be able to:
- Read and write numbers up to 1000
- Show numbers using hundreds, tens and ones
- Count groups of objects to find how many
What you already know
- Counting to 100 (Basic 1)
Copy everything that has a blue line on its left into your notebook. The other parts are for reading.
- Strand
- Number
- Sub-strand
- Counting, Representation and Cardinality
- Indicator
- B2.1.1.1.1 – Use number names ,counting sequences and how to count to find out how many
Introduction
The school has 345 pupils. How do we read and write a big number like that? We use hundreds, tens and ones.
1. Hundreds, Tens and Ones
10 ones make 1 ten. 10 tens make 1 hundred. 10 hundreds make 1 thousand.
| Hundreds | Tens | Ones |
|---|---|---|
| 3 | 4 | 5 |
345 is 3 hundreds, 4 tens and 5 ones.
We read it as "three hundred and forty-five".
2. Reading and Writing Numbers
| Number | Words |
|---|---|
| 120 | one hundred and twenty |
| 506 | five hundred and six |
| 999 | nine hundred and ninety-nine |
| 1000 | one thousand |
Example
Write 7 hundreds, 2 tens and 8 ones as a number.
- 7 hundreds = 700
- 2 tens = 20
- 8 ones = 8
Answer: 700 + 20 + 8 = 728
Common mistake: 506 has 0 tens. Do not forget the zero.
New words
- hundred
- Ten tens; 100.
- ten
- Ten ones; 10.
- ones
- Single units.
- thousand
- Ten hundreds; 1000.
Summary
- 10 ones = 1 ten; 10 tens = 1 hundred; 10 hundreds = 1 thousand.
- 345 is 3 hundreds, 4 tens and 5 ones.
- Use zero to hold an empty place, as in 506.
Class activity: Bundle Numbers
- Make bundles of 10 sticks and bundles of 100 sticks.
- Pick a number card and show it with bundles.
- Write the number and its name in words.
You need: Bottle tops, Bundles of sticks, Locally made number cards
Exercises
Answer in your exercise book first, then check your answers.
1. How many tens make one hundred?
- A. 10
- B. 5
- C. 100
- D. 1
Show answer
Answer: 1010 tens = 100.2. What number is 4 hundreds, 0 tens and 9 ones?
- A. 409
- B. 490
- C. 49
- D. 940
Show answer
Answer: 409400 + 0 + 9 = 409.3. 10 hundreds make 1000.
- A. True
- B. False
Show answer
Answer: TrueTen hundreds is one thousand.4. In 652, the 5 means 5 ones.
- A. True
- B. False
Show answer
Answer: FalseThe 5 is in the tens place, so it means 50.5. 300 + 60 + 2 = ______
Show answer
Answer: 3623 hundreds, 6 tens and 2 ones.6. Write 815 in words.
Show answer
Answer: Eight hundred and fifteen8 hundreds and 15.
Homework
- Find a big number at home (on a calendar or price tag). Write it in words.