1. Lesson 3-1 Rounding and Estimating

2. Writing Decimals 2. 3 2 9 8 4 Express 0.426 using words. And represents the decimal point Write two and three hundredths

3. Some real life problems require only an estimate while others require an exact answer. – A headline noting the number of people living in China. – The amount of money a baby sitter charges per hour. – The width of a window screen. – The distance from Earth to the moon. – The hours at football practice in one month. – The number of tickets sold for a play.

4. You can round decimals when you don’t need exact values. When rounding if the number to the right is 5 or greater---round up When the number to the right is less than 5 do not change the number

5. Round to the nearest hundredth 4. 7290.2729 Round to the nearest tenth 84.6391.182

6. ≈ means approximately equal to 126 ≈ 130 One way to estimate is to round all numbers to the same place 464.90 – 125.73

7. Front end estimating – add the front-end digits. Round to estimate the sum of the remaining digits. Then combine estimates. Carrots cost $2.71, peppers cost $1.73 and broccoli costs $1.10. Estimate the total cost of the vegetables

8. You can use clustering to estimate the sum of several numbers that are close to the same value