Here is how teaching subtraction to kindergarten works:

• By using images to learn subtraction.
• Put a few apples on the table in front of your child.
• Count them: one, two, three, four.
• Explain that we can represent apples as numbers – four apples equals 4.
• Take away two apples.
• Count the remaining fruit once again: one, two.
• We took away two from four, and two are left.
• Now, let’s pretend apples are numbered: 4 – 2 = 2.

By this way we can teach a child subtraction.