How many rocks?

How many rocks are there here?

If you had to guess, what would your answer be?

Go ahead and make a guess -

.

.

.

.

.

.

.

.

.

Okay, enough of the guessing and counting, we came up with 80, ten of which are black. Black pebbles where traded in Roxaboxen. Just to further the math concepts with Thing One, I had him come up with a few math problems that equal 80. Here's our list:

40 + 40
70 + 10
40 x 2
10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 (Thing Two wanted to contribute to the list!)
4 x 20
1 x 80
6 x 16
8 x 10

We could have spent a lot of time coming up with more, but this seemed like a reasonable amount for now. We've been working on finding the factors, in Math U See, when given the product. Was pleased to see that he found them all.