Counting Coins of One Kind

To count nickels, skip count by 5. To count dimes, skip count by 10.

Two different numbers

Four dimes is 4 coins, but 40¢. The number of coins is not the amount.

The coin chooses the step

Quarters go 25, 50, 75, 100. Pennies go one at a time.

One kind of coin means skip-counting

Six nickels? Count 5, 10, 15, 20, 25, 30 — thirty cents. Four dimes? 10, 20, 30, 40. When every coin is the same, counting money is exactly the skip-counting you practised in Chapter 3, with a unit attached.

Counting quarters

Quarters go 25, 50, 75, 100. Four quarters make one dollar. That sequence is worth memorising outright, because quarters appear constantly and counting by 25 is harder than counting by 5 or 10.

Pennies are just ones

Counting pennies is ordinary counting: 1, 2, 3, 4. That makes them the easiest coin but the slowest to count in quantity. This is exactly why bigger coins exist — so you do not have to carry a hundred pennies to buy a dollar's worth of anything.