Skip counting by 2, 5 and 10

Counting one-by-one works, but it is slow. Skip counting is when you jump in equal steps. It is the cool older sibling of counting.

Counting by 10

The easiest skip is by ten:

10, 20, 30, 40, 50, 60, 70, 80, 90, 100.

You already know this one — it is just the tens.

Counting by five is everywhere. Watches, hands, fingers on two hands.

5, 10, 15, 20, 25, 30, 35, 40, 45, 50.

Notice the trick: every number ends in 5 or 0. You can keep going to 100 the same way.

Counting by two gives you the even numbers:

2, 4, 6, 8, 10, 12, 14, 16, 18, 20, ... 100.

Try it on your fingers — count two fingers at a time.

It is fast. Counting eyes? Count by 2. Counting fingers? Count by 5. Counting people in a marching band? Count rows by 10.
It builds multiplication later. "5 + 5 + 5 = 15" is exactly the same as "3 times 5 is 15".

How many ten-cent coins make 50 cents?

Count by 10: 10, 20, 30, 40, 50. That is 5 coins.

How many five-cent coins make 25 cents?

Count by 5: 5, 10, 15, 20, 25. That is 5 coins.