Basic 2 · Mathematics · Counting, Representation and Cardinality
Odd and Even Numbers and Number Neighbours
In this topic you will sort numbers into odd and even and find numbers around a given number.
By the end of these notes you should be able to:
- Tell odd numbers from even numbers
- Find numbers just before, just after and between
- Find numbers 10 more and 10 less on a chart
What you already know
- Skip counting
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
- B2.1.1.1.2 – Identify numbers in different positions around a given number
Introduction
Share 6 oranges between 2 children. Each gets 3 and none is left. Share 7 oranges. One is left over. 6 is even and 7 is odd.
1. Odd and Even Numbers
Even number: A number that can be shared into 2 equal groups. It ends in 0, 2, 4, 6 or 8.
Odd number: A number that cannot be shared into 2 equal groups. It ends in 1, 3, 5, 7 or 9.
| Even | Odd |
|---|---|
| 4 | 7 |
| 18 | 23 |
| 250 | 149 |
2. Number Neighbours
| 10 less | Just before | Number | Just after | 10 more |
|---|---|---|---|---|
| 457 | 466 | 467 | 468 | 477 |
Remember: Look at the last digit to tell odd or even.
New words
- even
- Can be shared into 2 equal groups.
- odd
- Has one left over when shared into 2.
- digit
- One of the signs 0 to 9 used to write numbers.
- neighbour
- A number next to another number.
Summary
- Even numbers end in 0, 2, 4, 6 or 8.
- Odd numbers end in 1, 3, 5, 7 or 9.
- Just before is 1 less; 10 less is the number above on a chart.
Class activity: Odd One Out
- Mix number cards on the table.
- Pick out all the odd numbers.
- Put the even numbers in order.
You need: Bottle tops, Bundles of sticks, Locally made number cards
Exercises
Answer in your exercise book first, then check your answers.
1. Which number is even?
- A. 14
- B. 15
- C. 17
- D. 21
Show answer
Answer: 14It ends in 4.2. What is 10 more than 386?
- A. 387
- B. 396
- C. 486
- D. 376
Show answer
Answer: 396Add 1 to the tens digit.3. 9 is an odd number.
- A. True
- B. False
Show answer
Answer: TrueIt ends in 9.4. 230 is an odd number.
- A. True
- B. False
Show answer
Answer: FalseIt ends in 0, so it is even.5. The number just after 599 is ______.
Show answer
Answer: 600599 + 1 = 600.6. Write three even numbers between 20 and 30.
Show answer
Answer: Any three of 22, 24, 26, 28.They end in 2, 4, 6 or 8.
Homework
- Write your house number or age. Is it odd or even?