Adding Odd and Even Numbers

Odd and even

by Ms. Thơ

Poll

Paula says, ‘I added three odd numbers and my answer was an even number.’

• True

• False

​Try some examples of three odd numbers added together

​

Multiple Choice

1 + 3 + 5 = ?

• odd

• even

Multiple Choice

11 + 13 + 15 = ?

• odd

• even

Multiple Choice

9 + 7 +  = ?

• odd

• even

​You know that

​odd + odd = even

​If add another odd number , you get:

​even + odd = odd

​Adding three odd numbers always gives an odd answer, so Paula cannot be correct.

​

​A statement like this that uses odd to stand for any odd number and even to stand for any even number is called a generalisation or general statement. It works for all examples

Open Ended

Find three examples that match this general statement

"The sum of two even numbers is even"

Multiple Choice

When you add two odd numbers together the answer is _____.

• odd

• even

• odd and even

Multiple Choice

Which calculation shows the difference between two even numbers is even?

• 4 - 1 = 3

• 6 - 2 = 4

• 5 - 1 = 4

• 3 -2 = 1

Multiple Choice

Heidi says, ‘When you find the difference between two odd numbers the answer is odd.’ Is she correct?

• True

• False

Multiple Choice

Martha says, ‘I added three even numbers and my answer was 25.’

• True

• False

Open Ended

Salem says, ‘When you add 5 to any number the answer will be odd.’ Is he correct?

Explain how you know.

Multiple Choice

The sum of two even numbers is 18.

• right

• wrong

Multiple Choice

The sum of three odd numbers is 22.

• right

• wrong

Multiple Choice

The sum of two odd numbers is 20.

• right

• wrong

Multiple Choice

The sum of three even numbers is 24.

• right

• wrong

Multiple Choice

Here are some statements. Which one is incorrect?

• even + even = even

• even - even = even

• odd + odd = odd

• odd - odd = odd

​REMEMBER

• ​odd + odd = even

• ​odd - odd = even

• ​even + even = even

• ​even - even = even​

• ​even + odd = odd

• ​even - odd = odd

• ​odd - even = odd