A number is odd if we cannot split it into groups of two with nothing left over.
If we try to split these 9 squares into groups of 2, there is always one left over. So, 9 is odd.
Which of the following numbers is odd?
Here are 57 dots. Is 57 even or odd?
Is 16 even or odd?
Is the number of circles in the figure even or odd?
Isabella is using ten frames to see if 14 is even or odd.
She knows that even numbers can be grouped into pairs, so she colors 14 squares in two ten frames and tries to see if every square has a partner.
She notices that the first ten frame is full and can always be grouped into pairs. So, to decide if the number is odd or even, she needs to look at the second ten frame, which is the ten frame for the unit digit.
Now it is your turn. Is 17 even or odd? Why?
Here are 46 dots. Is 46 even or odd?
Every child has a partner to work with.