I have realised with Pink that when she learns a concept by “doing” an activity as opposed to a worksheet she tends to understand it.
I started introducing the idea of Odd and Even numbers a few months ago just be casually getting her to look at the numbers on the houses on our side of the street (all even) and then on a different day the numbers on the other side (all odd). This simple excercise also really helped with her counting in 2’s and now she will often do it by herself when we walk home.
The first set activity that we did when we started learning about Odds and Evens is in the picture below. We wrote the numbers on the lolly sticks making sure that we wrote all even numbers in a different colour to the Odd numbers. Pink then used her playdough to make them into a number line.
We also found this great printout (free) from the Free Homeschool Deals website, part of the apple pack. It was a good introduction to Odd and Even numbers as the apples are colour coded
I then made her a simple butterfly worksheet. I wrote the words Odds on one side and Even on the other and she went through her numbers from 1 to 20 deceiding on which wing they belonged. While she was doing this I could see that it was really starting to sink in.