1. What is a Decimal?

2. What is a decimal? A decimal is similar to a fraction – It’s not a whole number. Rather than saying ½, we can say 0.50 Instead of writing 1/10, we can say one-tenth or 0.1. It’s simply another form of a fraction.

3. What is a decimal? A decimal is a part of a number. We use decimals most often when we are talking about money. $13. 45 How would you read this number?

4. $13.45 Thirteen dollars and forty five cents. Remember: You do not need to use the ¢ when your money amount is greater than $1.

5. What does the.45 mean?.45 is the same thing as saying 45¢. It means that it is only a part of a dollar. It is not the whole dollar.

6. Why do I have to understand decimals? This is a good question. We need to understand what the value of each number means in order to understand what we are talking about. Here is an example: A shirt costs $12.05, but when I wrote the number down I wrote $12.5. What’s wrong with this?

7. Why is $12.5 wrong? $12.5 really is saying $12.50, because when we read how much something costs it always has two places after the decimal point. If we don’t have a digit after the first number we must assume it is a zero. However, when we read $12.05, the zero is the place holder so we know it is 5¢ and not 50¢. That is a 45¢ difference. I can get a piece of gum for that amount!

8. Let’s Look at Some Place Value One Hundred Dollars Ten Dollars One Dollar Ten Cents Cents 13782 HundredsTensOnesTenthsHundredths 13782 AND

9. How do I read a decimal? If you look at the number 12.3, you say: Twelve and three tenths. If you look at the number 12.35, you say: Twelve and thirty-five hundredths. If you look at a number 12.05, you say: Twelve and five hundredths. Now you practice saying them!

10. Let’s Write these Numbers in Expanded Form $100 + $30 + $7 + 80¢ + 2¢ = $137.82 If we are using money, it would look like this: If we are using decimals, it would look like this: 100 + 30 + 7 +.8 +.02 = 137.82

11. How do I Compare and Order decimals? 7.3 and 7.03 – Which is larger? ORGANIZE – Write the numbers vertically by lining up the decimal points. 7.3 7.03 EQUALIZE – Add a zero to make the numbers all have the same number of digits 7.30 7.03 ORDER – Start with the largest place and compare the decimals. 7.30 > 7.03

12. Compare and Order – Another Example Order from least to greatest: 12.34; 12.4; 12.43; 12.3 ORGANIZE – Write the numbers vertically by lining up the decimal points. 12.34 12.4 12.43 12.3 EQUALIZE – Add a zero to make the numbers all have the same number of digits 12.34 12.40 12.43 12.30 ORDER – Start with the largest place and write the decimals in order. 12.30; 12.34; 12.40; 12.43

13. When else do we use decimals? Weight (He weighed 85.5 lbs) Temperature (It was so cold today, it was only 43.7°) Measuring distances (example: the race was a 5 kilometers or 3.1 miles long Can you think of any other times?