Problem Solving

We had a real problem on Friday.

Here it is ...

There are 20 children in Room 15, each child needs 4 hubcaps for their corrugated cardboard truck.

How many hubcaps do we need to cut and paint?

So ...  here's what we did...

On our mat we counted out 20 squares, then we put 4 bottle tops on each square.  Then we started counting...

Here we are counting in 1's.  There was lots of counting going on.  

Here are our first counts,

57, 68, 69, 74, 75, 77, 79 and then 80.

Well done Kai, yes we needed to cut out and paint 80 hubcaps.

What other ways could we have worked this problem out?