I drew a picture!!
.
Maybe you didn't.
.
I like to picture things though.
.
Ok, a rectangle cut in half.
.
Ok, by definition of "half," just multiply the number of rectangles by 2.
.
1 x 2 = 2 after cutting the brownies in half.
.
2 x 2 = 4 after cutting it in half again.
.
4 rectangles now!!
.
Doing it the other way... pretend you are starting over from scratch.
.
A new batch of brownies!
.
But still pay attention to what you already cut.
.
Cut down the middle the other direction.
.
What's 4 x 2?
.
8.
.
Now, finally, we multiply the half of the half brownies.
.
What's 8 x 2?
.
16.
.
16 slices.
.
Maybe you didn't.
.
I like to picture things though.
.
Ok, a rectangle cut in half.
.
Ok, by definition of "half," just multiply the number of rectangles by 2.
.
1 x 2 = 2 after cutting the brownies in half.
.
2 x 2 = 4 after cutting it in half again.
.
4 rectangles now!!
.
Doing it the other way... pretend you are starting over from scratch.
.
A new batch of brownies!
.
But still pay attention to what you already cut.
.
Cut down the middle the other direction.
.
What's 4 x 2?
.
8.
.
Now, finally, we multiply the half of the half brownies.
.
What's 8 x 2?
.
16.
.
16 slices.