Even or odd: arithmetic rules
key notes :
Even Number:
An even number is any integer that is exactly divisible by 2, meaning there is no remainder when divided by 2.
Examples of even numbers: 2, 4, 6, 8, 10, …
Odd Number:
An odd number is any integer that is not divisible by 2 without leaving a remainder
Examples of odd numbers: 1, 3, 5, 7, 9, .
💡A simple addition or subtraction may reveal whether the resulting total or difference is odd or even, provided you are familiar with the Even or Odd arithmetic rules.
🥏Here are the rules for adding/subtracting even and odd numbers:
🔷Even or odd: arithmetic rules -Addition
| even | + | even | = | even |
| odd | + | odd | = | even |
| even | + | odd | = | odd |
| odd | + | even | = | odd |
🔷Even or odd: arithmetic rules -Subtraction
| even | − | even | = | even |
| odd | − | odd | = | even |
| even | − | odd | = | odd |
| odd | − | even | = | odd |
Examples :
| Example | Arithmetic rules |
|---|---|
| 56+8 =64 | even + even = even [64] |
| 79+10 =89 | odd + even = odd [89] |
| 55+5 =60 | odd + odd = even [60] |
| 12+5 =17 | even + odd = odd [17] |
| 10-2 =8 | even – even = even [8] |
| 88-5 =83 | even – odd = odd [83] |
| 97-17 =80 | odd – odd = even [80] |
| 77-12 =65 | odd – even = odd [65] |
| 86+0 =86 | even + 0 = even [86] |
| 86-0 =86 | even – 0 = even [80] |
| 55+0 =55 | odd + 0 = odd [55] |
| 55-0 =55 | odd – 0 = odd [55] |
Learn with an example
🔴Is 74 + 16 even or odd?
- even
- odd
74 is even. 16 is even.
Use the rule:
even + even = even
74 + 16 is even.
Now check your answer by doing the maths.
74 + 16 = 90
Yes, the answer is even. 90 ends in a 0, which makes it even.
🔴 Is 59 − 13 even or odd?
- even
- odd
59 is odd. 13 is odd.
Use the rule:
odd − odd = even
59 − 13 is even.
Now check your answer by doing the maths.
59 − 13 = 46
Yes, the answer is even. 46 ends in a 6, which makes it even.
🔴 Is 43 + 49 even or odd?
- even
- odd
43 is odd. 49 is odd.
Use the rule:
odd + odd = even
43 + 49 is even.
Now check your answer by doing the maths.
43 + 49 = 92
Yes, the answer is even. 92 ends in a 2, which makes it even.
🔴 Is 82 − 75 even or odd?
- even
- odd
82 is even. 75 is odd.
Use the rule:
even − odd = odd
82 − 75 is odd.
Now check your answer by doing the maths.
82 − 75 = 7
Yes, the answer is odd. 7 is an odd number.
🔴 Is 13 + 82 even or odd?
- even
- odd
13 is odd. 82 is even.
Use the rule:
odd + even = odd
13 + 82 is odd.
Now check your answer by doing the maths.
13 + 82 = 95
Yes, the answer is odd. 95 ends in a 5, which makes it odd.
Let’s practice!
