### Unit 4: Decimals

In this unit, you will turn your attention to the "fraternal twin" of fractions: decimals. Yes, decimals are really just fractions in disguise! Who knew? For example, look at (American) money. A dollar is 100 cents; a quarter is 25 cents, or in decimal form, $0.25. The fraction 25/100 reduces to 1/4, which is read as "one-quarter." Decimals are fractions, and fractions are decimals. It's all in how you write them.

Decimals are everywhere, just like fractions. You cannot go shopping without encountering decimals. Whether you are adding up totals on your shopping list, calculating your change, or even just measuring the length of something, you will use decimals. If you add up all your purchases, find that your total comes to $17.31, and you hand the cashier $20, you need to know how to determine your change to make sure the cashier gives you back the correct amount of money. If you are measuring the length of your wall in order to fit a couch there, you might find that the wall's length is in between two lengths, measuring at, say, 11.5 ft. You have to know how to deal with decimals to approximate distances.

In this unit, you will learn how to add/subtract/multiply/divide decimals as well as how to convert between fraction and decimal form.

**Completing this unit should take you approximately 26 hours.**