Here's an easy one for you!

Haha!  I love easy math problems!

Can you do this?

In first grade, they told you that you couldn't do problems like this so you wouldn't get confused and start crying!  But, you're older now and can handle the truth...

Yes, you CAN subtract a big number from a smaller one!  But, we need a new set of numbers to do it.

Up till now, you've been working with whole numbers...

and fractions and decimals -- which fill in all of the gaps between those whole numbers...