6.7

Pg 41 Estimation Directions This is actually the easiest of word problems. Estimate BEFORE doing the math!!! Key words- ABOUT, CLOSEST, APPROXIMATELY, GENERALLY, NEARLY, ALMOST Once numbers needed in the word problem are estimated, then do the math! Underline key words and the question. Draw a picture to help understand. Example- Bicycle- one is about $ Bicycles- So 8 bicycles would be 8 X 300= 2, pg 42 Rational number - the set of numbers that can be written as a ratio or fraction. All integers are rational, finite (terminating) and repeating decimals too. Example- 1/3, -8, 5, 4.75 What is NOT rational would be pi (π) 3.14….. which does not terminate nor repeat. Compatible number –Numbers that are easy to divide naturally are compatible numbers, used when estimating. Example: 102/24 is easier to estimate when you think 100/25 (these are the compatible numbers) Budget - A plan for the expenditure (spending) of a fixed resource, such as money or time, during a given period. Example: A new car will not be part of our budget this year. Front-end estimation –You add or subtract the first numbers, then add or subtract the numbers in the next place value. Basically, pay attention to the first number and ignore the rest (EASY!) = =800 Rounding – Changing numbers to a common place value. Example- determine what they want you to round to by checking out the multiple choice answers. Determine rounding to the nearest hundreds = = 900, or round to the nearest tens = = 930 depending on what the multiple choice answers are. Key words to determine operation in a word problem Addition- altogether, sum of, total in all, combined, increased, add Subtraction- more, less than, difference, decreased, fewer than, cut, used, less, minus, need to, remains, subtracts AND ANYTHING WITH ER (same as more) meaning you are comparing two things (finding the difference) Multiplication- of, times, product of, multiplied by, increased, at this rate Division- per, split, divide, each

pg 44 Remember to look for key words- ABOUT, CLOSEST, APPROXIMATELY, GENERALLY, NEARLY, ALMOST and estimate BEFORE doing the actual math. Estimating- If a number is 1-4, round down. If a number is 5-9, round up. Examples- Rounding to nearest tens. 5 is is is is 20. Rounding to nearest hundreds- 249 is is 300. Money rounded to the nearest dollar, anything with at least 50 cents rounds up, less than 50 cents rounds down. If a fraction or decimal is less than ½, round down. If ½ or more round up. Round to the nearest tens 1.2, $17.43 Round to the nearest hundreds 1.2, $3, Round to the nearest whole 1.1/3 2.6/ $5.25 Pg 43 PRACTICE Mr. Green remembered the area of his living room wall to be between 230 and 260 square feet. Which could be the dimension of his wall? A 22 feet x 8 feet B 24 feet x 9 feet C 25 feet x 10 feet D 30 feet x 12 feet Tommy was paid $22.50 for washing his father’s car. If he spends $7.25 on a hamburger and fries, $2.50 on candy, and $8.89 to rent two movies, about how much money will he have left? A.$4.00 B.$19.00 C.$1.00 D.$13.00