1. Rounding Numbers Review ofBasicArithmetic

2. Section 1.1 Topics Section 1.1: Place Value of Numbers Section 1.1: Rounding Numbers Section 1.2: Factors and Multiples Section 1.3: Fractions Section 1.4: Order of Operations (BEDMAS) Section 1.5: Averages Section 1.1: Place Value of Numbers Section 1.1: Rounding Numbers Section 1.2: Factors and Multiples Section 1.3: Fractions Section 1.4: Order of Operations (BEDMAS) Section 1.5: Averages

3. Section 1.1 Rounding Whole Numbers and Decimals Rounding changes some of the digits in a number but keeps its value close to the original. Example Example The population of the world is approximately 6.78 billion. Ralph’s food expenses are approximately $300 per month. His actual food expenses could be $315 one month, $291.95 the next month, and so on. That is not, of course, the exact number (which is more like 6,775,235,700, according to a World Bank estimate in 2009).Rounding the number makes it easier to remember and to work with.

4. Section 1.1 Rules for Rounding Whole Numbers Rounding whole numbers refers to changing the value of the whole number to the nearest ten, hundred, thousand, etc. Example Round 73,423 to the nearest ten. If the digit to the immediate right of the rounding digit is less than 5, do not change the value of the rounding digit. Change the value of all digits that are to the right of the rounding digit to 0. 0 73,4 2 3 Digit is less than 5 73,423 rounded to the nearest ten is 73,420. 2 is the rounding digit

5. Section 1.1 Rules for Rounding Whole Numbers Rounding whole numbers refers to changing the value of the whole number to the nearest ten, hundred, thousand, etc. Example Round 25,578 to the nearest ten. If the digit to the immediate right of the rounding digit is 5 or greater than 5, increase the value of the rounding digit by one (round up by one number). Change the value of all digits that are to the right of the rounding digit to 0. 8 0 25,5 7 8 Digit is greater than 5 25,578 rounded to the nearest ten is 25,580. 7 is the rounding digit

6. Section 1.1 Round 52,876 to the nearest hundred. 52,870 52,880 52,700 52,900

7. Solution Round 52,876 to the nearest hundred. 876 900 52 , Digit is greater than 5 8 is the rounding digit 52,876 rounded to the nearest hundred is 52,900.

8. Section 1.1 Round 75,298 to the nearest ten. 75,200 75,300 75,290 74,000

9. Solution Round 75,298 to the nearest ten. 75, 298 300 When 9 is increased by one, the digit to its left also has to be increased by one. Digit is greater than 5 9 is the rounding digit 75,298 rounded to the nearest ten is 75,300.

10. Section 1.1 Rules for Rounding Decimals Rounding decimals refers to changing the value of the decimal number to the nearest whole number, tenth, hundredth, thousandth, etc. Example Round 12.675 to the nearest tenth. If the digit to the immediate right of the rounding digit is 5 or greater than 5, increase the value of the rounding digit by one (round up by one number). Drop all digits that are to the right of the rounding digit. 5 7 12. 6 7 Digit is greater than 5 12.675 rounded to the nearest tenth is 12.7. 6 is the rounding digit

11. Section 1.1 Round 372.137 to the nearest hundredth. 372.140 372.14 372.130 372.13

12. Solution Round 372.137 to the nearest hundredth. 372.1 37 4 Digit is greater than 5 3 is the rounding digit 372.137 rounded to the nearest hundredth is 372.14

13. Section 1.1 Round $157.343 to the nearest cent. 157.350 157.35 157.340 157.34

14. Solution Round $157.343 to the nearest cent. 3 157.34 Digit is less than 5 Rounding to the nearest cent means rounding to two decimal places. 4 is the rounding digit(cent) $157.343 rounded to the nearest cent is $157.34.