Show:
GCF and LCM
Dividing Fractions
Multiplying Decimals
Dividing Whole numbers + Decimals
100

What is the GCF of 12 and 20?

4

100

When I am dividing a fraction by a mixed number, what must I do first?

Convert the mixed number to improper fraction

100

What is 1 advantage and 1 disadvantage of the partial product method? 

Advantage = mental math, easier to solve

Disadvantage = only works for specific numbers, keep track of decimal point

100

What must you do first when you have a decimal point in the divisor? How?

Get rid of the decimal point in the divisor by multiplying by a power of 10.
200

What is the LCM of 8 and 16?

16

200
What does keep, change, flip actually mean?

Multiply by the reciprocal!

200

200 x 12.2

2440

200

3.675 ÷ 1.05

Using the method of multiplying with powers of ten, write an equivalent expression for this problem.

367.5 ÷ 105

36.75 ÷ 10.5

3675 ÷ 1050

(Which of these can you actually use to divide efficiently?)

300

At a local bakery, Bob decorated 7 cakes at a time. Susan decorated 11 at a time. If they ended up decorating the same number of cakes by the end of the day, what is the smallest number of cakes that each must have decorated?

77

300

3/7 ÷ 2  1/2 

6/35

300

25.6 x 12.5

320.00 or 320

300

3500 ÷ 1,660 

Round to the nearest tenths

2.1

400

Henry is packing equal numbers of apple slices and grapes for snacks. Henry bags the apple slices in groups of 10 and the grapes in groups of 5. What is the smallest number of grapes that he can pack?

10
400

20 3/5  ÷  4/8 

Write your answer as a mixed number.

41 4/20 or 41 1/5

400
Error Analysis: Ms. Bentil solved for 4.9 x 3.8. She lined up her decimal points and got 186.2 as her answer. What was the error and how can she fix it? 

Error = she just brought down the decimal point as if she was adding or subtracting 

Fix = count the number of digits after the decimal points in the problem and add them up. That is the number of digits after the decimal point in the product. 

400

55.318 ÷ 3.4

16.27

500

Evan has 36 baseballs and 76 basketballs. If he wants to divide them into identical groups without any balls left over, what is the greatest number of groups Evan can make?

4

500

50 1/4 ÷ 20 4/5

Write your answer as a mixed number.

2 173/416

500

You are solving 12.9 x 3.42 quickly and forgot to keep track of your decimal point. Your answer is 44118. Come up with two different strategies that will help you place the decimal point in the correct spot. 

1) Count digits after decimal place (1 + 2 = 3)

2) Estimate (13 x 3 = 39)

500

Describe, correct, and solve the error in rewriting the problem:

Original Problem: 146.4 ÷ 0.32

Rewritten as: 146.4 ÷ 32

Describe: Did not keep the balance; Moved the decimal in the divisor but not the dividend

Correct: 14640 ÷ 32

Solve = 457.5