Dividing Decimals by Other Decimals Unit 3.7 Pages 126-128

Warm Up Problems Divide 4.8 2 = 16.1 7 = 0.36 3 = 4. 25.28 4 = 2.4 2.3 0.12 6.32

45 76 3420 What number is the divisor? What number is the quotient? What number is the dividend? 45 76 3420

3.7 Dividing Decimals by Decimals. Objective: by the end of class students can change a divisor with decimals into a whole number and then divide into the dividend to find the quotient.

We follow the same rules for dividing whole numbers, as we divide numbers with decimals in them. 0 1 5 - 5 2 5 -2 5 0 1 5 - 5 2 5 -2 5 5 075 5 0.75

Dividing by a Decimal Number 0 0 6 - 0 4 2 -4 2 This time the DIVISOR will have a decimal in it. We will need to change it into a whole number first by moving the decimal to the right side. 0 7 0 4 2

Dividing by a Decimal Number 0 0 6 - 0 4 2 -4 2 Now we must multiply the DIVIDEND by 10 too! When we do this the decimal will now move to the right 1 space. When we changed the divisor to a whole number we multiplied it by 10. That is why the decimal moved from a part of a whole to a whole x 10 0 7 0 4 2 x 10

0 3 -0 Find each Product 3.6 1.2 =3 Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend. 1.2 3.6 3 6 First divide the equation like you normally would. -3 6 Place the decimal point directly above in the quotient.

0 5 -0 Find each Product 7.5 1.5 =5 Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend. 1.5 7.5 7 5 First divide the equation like you normally would. -7 5 Place the decimal point directly above in the quotient.

0 9 -0 Find each Product 9.9 1.1 =9 Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend. 1.1 9.9 9 9 First divide the equation like you normally would. -9 9 Place the decimal point directly above in the quotient.

TRY ESTIMATING DOUBLE DIGIT NUMBERS FIRST! 0 7 -0 Find each Product 10.5 1.5 =7 Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend. 1.5 10.5 ~20 First divide the equation like you normally would. TRY ESTIMATING DOUBLE DIGIT NUMBERS FIRST! 1 0 5 -1 0 5 Place the decimal point directly above in the quotient.

TRY ESTIMATING DOUBLE DIGIT NUMBERS FIRST! 0 4 -0 Find each Product 20.4 5.1 =4 Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend. 5.1 20 4 ~50 First divide the equation like you normally would. TRY ESTIMATING DOUBLE DIGIT NUMBERS FIRST! 2 0 4 -2 0 4 Place the decimal point directly above in the quotient.

TRY ESTIMATING DOUBLE DIGIT NUMBERS FIRST! 0 4 -0 Find each Product 20.4 5.1 =4 Count the total number of decimal places in the divisor and move the decimal the same amount of spaces in the dividend. 5.1 20 4 ~50 First divide the equation like you normally would. TRY ESTIMATING DOUBLE DIGIT NUMBERS FIRST! 2 0 4 -2 0 4 Place the decimal point directly above in the quotient.

Homework (3.7A) page 131-132 Due: Friday 1-26

0 5 Let’s do a few together #1) Find each Product 6.5 1.3 =5 1.3 6.5

034 5 Let’s do a few together #2) Find each Product 20.7 0.6 0.6 20.70 =34.5

017 Let’s do a few together #3) Find each Product 25.5 1.5 1.5 25.5 =17

0 6 Let’s do a few together #4) Find each Product 5.4 0.9 0.9 5.4 =6

0 6 Let’s do a few together #5) Find each Product 2.2 13.2 2.2 13.2 =6

0264 125 #6) Find each Product 63.39 0.24 0.24 63.39 000 =264.125

Marcus drove ____ miles/hours? #7. Marcus drove 354.9 miles in 6.5 hours. On average, how many miles per hour did he drive? = 354.9 miles 1 hr 1 hr 1 hr 1 hr 1 hr 1 hr ½ 1 hr Marcus drove ____ miles/hours?

Homework (3.7A) page 131-132 Due: FRIDAY! 1-20

Dividing by decimals Day Two Unit 3.7 Pages 129-132

Marcus drove ____ miles/hours? #8. Anthony spends $87.75 on shrimp. The shrimp cost $9.75 per pound. How many pounds of shrimp does Anthony buy? = $87.75 = 1 lb $9.75 Marcus drove ____ miles/hours?

45 76 3420 What number is the dividend? What number is the quotient? What number is the divisor? What number is the divisor? 45 76 3420

*Get into groups of two or three. *Place the number cards face down on the desk. *Pick up 2 cards to be your divisor and 3 cards to be the dividend.

*Take turns placing 2 plastic chips between each number to represent decimals. *Preform the division and share your answers.

3.7 Dividing Decimals by Decimals. Objective: by the end of class students can change a divisor with decimals into a whole number and then divide into the dividend to find the quotient using powers of 10 and variables.

Dividing by using a variable 012 2 0.732 n n 0.732 .06 n=0.06 -6 13 -12 Substitute the variable for the number given. And divide as you would with whole numbers. 12 -12

56 78 c 73.814 1.3 c=1.3 73.814 c # 28 Find each quotient Replace the variable with the given number. Count the total number of decimal places in the dividend. Place the decimal point directly above in the quotient. Then divide the equation like you normally would.

2 # 31. 6.35 x 10 0.5 635 0.5 P E M D A S 0.5 6350.

2 # 32. 8.1 x 10 0.9 810 0.9 P E M D A S 0.9 8100.

Homework (3.7B) page 131-132 Due: Monday 27-36

I spent $13.44 renting 4 videos. What was the cost per video? 21.63 2.1 38.43 6.1 Find each quotient 10.3 6.3 16.9 5.2 I spent $13.44 renting 4 videos. What was the cost per video? 3.25 $3.36