3–4 Estimating Sums and Differences - My Math 6 - Home

1 Math Connects, Course 1 63 Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, 4 Estimating sums and DifferencesMAIN IDEA Estimate sums and Differences of decimals. EXAMPLES Use Estimation to Solve ProblemsPOPULATION The table below shows the population of the American colonies in (thousands)ColonyPopulation(thousands) Island Hampshire : The World Almanac Estimate the total population of North Carolina and South each number to the nearest hundred for easier adding. rounds to . ____ + _____ + rounds to . There were about thousand people in North Carolina and South Carolina. Estimate how many more people lived in Rhode Island than in Georgia in 1770. Round each number to the nearest ten for easier subtracting. rounds to . ____ + _____ - rounds to . 40 There were about 40 thousand more 630055-0084 6311/29/07 11:18:06 AM11/29/07 11:18:06 AM3 464 Math Connects, Course 1 Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Your ProgressRefer to the table that shows the population of the American colonies in 1770.

2 A. Estimate the total number of people in Pennsylvania and New Jersey in 1770. b. Estimate how many more people were in Massachusetts than in is an estimation method in which a group of numbers that are in value are to the same YOUR VOCABULARY (page 56)EXAMPLE TEST EXAMPLE Sid feeds a vitamin-water solution to his guinea pigs. The table shows the amount of solution the guinea pigs drank over a period of four days this week. Which is the closest to the amount of solution the guinea pigs drank?Amount of Vitamin-Water Solution Guinea Pigs Drink Each DayDayAmount (ounces) 40 ounces B 60 ounces C 80 ounces D 100 ouncesORGANIZE ITUnder Lesson 3-4 of your Foldable, describe a situation in which you estimated a decimal sum or 3:OperationswithDecimals 0055-0084 640055-0084 6411/29/07 11:18:07 AM11/29/07 11:18:07 AM3 4 Math Connects, Course 1 65 Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, the ItemThe addends are clustered around.

3 Round each decimal to . 20 Solve the ItemMultiplication is repeated addition. So, a good estimate is4 20, or . The answer is .Check Your ProgressMULTIPLE CHOICE During the month of February, Jonathon spent $ on gasoline the fi rst week, $ on gasoline during the second week, $ on gasoline during the third week, and $ on gasoline during the fourth week. Which is closest to the total amount Jonathon spent on gasoline during February? F $35 G $50 H $60 J $100 When you use front-end estimation, you the values of the digits in the front YOUR VOCABULARY (page 56)EXAMPLE Use Front-End Estimation Estimate + using front-end the digits. ___ + ____ + Using front-end estimation, + is about .Check Your Progress Estimate + using front-end ITWhen should you use clustering to estimate?

4 HOMEWORKASSIGNMENTPage(s):Exercises:0055 -0084 650055-0084 6511/29/07 11:18:07 AM11/29/07 11:18:07 AM