Here's another one:

3x5=

This means that you have three groups of 5!

15 pentagons split into 3 sets of 5 pentagons

Put the three groups together...  How many pentagons do you have?

15 pentagons

Count them...  Wow, that's a lot!  I see 15!

So, our answer is:

3x5=15


Let's switch the numbers around and do it the different way!

5x3=

This means that you have five groups of 3!

15 circles split into 5 sets of 3 circles

Put the five groups together...  How many purple circles do you have?

15 circles

Count them...  Yep, we get 15 again!  Cool!

5x3=15