Ways to 100

Formal multiplication instruction, at PDS as elsewhere, is generally the province of third, fourth, and fifth grades. But informally, multiplying comes up considerably earlier than that.

Our kindergarteners recently sorted collections of objects into groups of two, three, or more to see how many groups they had and how many were left over--multiplicative thinking at work. Counting quarters, dimes, or nickels uses simple multiplication concepts. So does telling time on an analog clock.

For that matter, any time children read, write, or model two- or three-digit numbers, they're using basic ideas of multiplication. Our decimal system, after all, is built on groups--groups of ones, tens, hundreds, and on and on.

The pictures below show groupings of 100 objects created by first and second graders. You can see the connection to multiplication: ten groups of ten, two groups of 50, five groups of 20, even 25 groups of four (though one of the dice here appears to have fallen off). Work like this can help children considerably when it's time for a formal introduction of the topic.

You may want to enlarge this last one to see what numbers are on the dice...