Make Ten is about the pairs of numbers that add up to ten: one and nine, two and eight, three and seven, and so on. Teachers call them number bonds, and they are among the most useful facts a young child can learn.
What your child is learning
Our whole number system is built on tens. A child who knows instantly that six needs four more to make ten will find later arithmetic much easier. Adding eight and five, for instance, becomes "eight and two is ten, and three more is thirteen".
The picture used here is called a ten frame: two rows of five squares. It is a standard classroom tool, because the empty squares show the missing number without any need to calculate.
How to help
Count the empty squares at first. That is exactly what the frame is for.
Point out the rows. The top row holds five. If the top row is full and there is one counter below, that is six, and four squares are empty. Seeing five as a chunk speeds everything up.
Use hands. Ten fingers make a perfect model. Hold up six and ask how many are folded down.
Say the pair both ways round. "Six and four make ten. Four and six make ten."
Taking it further
Play "make ten" with playing cards. Turn over a card and race to say its partner.
Once the bonds are quick, ask the take-away version: ten take away six?
There are only nine questions in the whole game, and a round asks eight of them, so the same facts come round often. That repetition is the point. It is one of the most practical HTML5 games here for children in their first years of school.