Name: ________________________________________________ Date:________________________ LESSON 51: MENTALLY DIVIDING DECIMAL NUMBERS BY 10 AND BY 100 Saxon 7/6 page 251 *When we divide, numbers get ______________________! Ex: 12.5 ÷ 10 = 1.25 12.5 ÷ 100 = 0.3 *When divide decimals by 10 and 100, count the ____________________ and move the decimal that many places to the LEFT. Ex: 37.5 ÷ 10 = 37.5 ÷ 100 = **moving the decimal to the left will make the number ___________________________. *Where is the decimal in a whole number? All the way to the _________________. All numbers have a decimal even if it is not written. Ex: 34 = 34. 8= 390= 1004= PRACTICE: Mentally divide and write your answer as a decimal. a. 2.5 ÷ 10 = b. 2.5 ÷ 100 = c. 87.5 ÷ 10 = d. 87.5 ÷ 100 = e. 0.5 ÷ 10 = f. 0.5 ÷ 100 = g. 25 ÷ 10 = h. 25 ÷ 100 = Name: ________________________________________________ Date:________________________ LESSON 52: DECIMALS CHART ■ SIMPLIFYING FRACTIONS Saxon 7/6 page 254 DECIMALS CHART + Line up the decimal points. x ÷ by whole number Multiply. Then count Decimal point moves up. decimal places. 1. Place a decimal point to the right of a whole number. 2. Fill empty places with zeros. ÷ by decimal Over, over, up. Simplifying Fractions Means: a.) Reducing to lowest terms b.) Changing improper fractions to mixed numbers 2 Example: 3 + 5 2 6 3 + x 2 2 = 4 6 5 5 6 6 9 6 REDUCE = 3 2 CONVERT = 2) 3 PRACTICE: a. Discuss how the rules in the decimals chart apply to each of these problems. Solve each problem. 5 - 4.2 .04 x 0.2 0.12 ÷ 3 5 ÷ 0.4 b. Fill in the decimal chart. + - x ÷ by whole number ÷ by decimal 1. Place a decimal point _______________________________________________________. 2. Fill empty places ___________________________. Add then simplify: c. 5 6 + 5 12 d. 9 10 + 3 5 e. 2 3 + 7 12 Name: ________________________________________________ Date:________________________ LESSON 53: MORE ON REDUCING ■ DIVIDING FRACTIONS Saxon 7/6 page 258 **Reduce by crossing off numbers that are the same in the numerator and denominator. 2∙2∙3∙5 Example: 2∙2∙3 5 = 2 2∙2∙2∙5 Example: Example: = 2 ∙ 2 ∙ 3∙ 5 How many 3 4 ÷ =5 1 3 1 3 ’s are in 4 ? 2 1 3 2 4 x **This is a ____________________ problem. 1 3 2 4 Change multiplication to division Example: How many 3 x 2 1 = 6 4 = 3 2) 3 2 Multiply and reduce Reciprocal of the 2nd fraction 1 ’s are in 2 ? 4 Practice: a. 2∙2∙3∙5 b. 2∙2∙5 c. How many 3 1 ’s are in 2 ? 8 2∙2∙3∙3∙5 2∙2∙3∙5∙5 d. How many 1 3 ’s are in 8 ? 2 Name: ________________________________________________ Date:________________________ LESSON 54: COMMON DENOMINATORS, PART 1 Saxon 7/6 page 265 *When the denominators of two or more fractions are the ___________, we say the fractions have COMMON DENOMINATORS. 1 Examples: 8 1 8 and + 3 8 3 2 8 5 2 = 5 and 3 4 5 9 3 = 4 + 5 9 and - 3 9 3 ? = *When _________________________ and ___________________________ fractions, you must have COMMON DENOMINATORS. Example: 1 2 + 3 1 4 2 + x 2 2 = 2 **Rename 4 3 3 4 4 5 1 2 by multiplying by CONVERT = 4) 5 = 1 4 Example: 1 2 - 1 1 6 2 - x = 3 6 1 1 6 6 2 6 **Rename 1 2 REDUCE = Practice: a. 1 + 3 d. 1 - 1 2 8 2 4 b. 3 + 1 e. 5 - 1 8 4 8 4 c. 3 + 1 4 8 f. 3 - 3 4 8 1 4 2 2 Name: ________________________________________________ Date:________________________ LESSON 55: COMMON DENOMINATORS, PART 2 Saxon 7/6 page 270 *Sometimes we need to rename both fractions before we can add or subtract. Example: 1 2 + 1 1 3 3 3 2 3 6 1 2 2 3 2 6 x = + x = 1 3 1 2 **Rename 2 by multiplying by 3 **Rename 3 by multiplying by 2 5 6 Example: 3 4 - 2 3 3 4 x = - x = 2 3 9 12 8 12 **Rename **Rename 3 4 2 3 1 12 Practice: a. 2 + 1 d. 2 - 1 3 2 3 4 b. 1 + 2 e. 1 - 1 4 5 3 4 c. 3 + 1 4 3 _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ N. Taylor