GCF and LCM
What is the GCF of 12 and 20?
4
When I am dividing a fraction by a mixed number, what must I do first?
Convert the mixed number to improper fraction
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
What must you do first when you have a decimal point in the divisor? How?
What is the LCM of 8 and 16?
16
Multiply by the reciprocal!
200 x 12.2
2440
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?)
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
3/7 ÷ 2 1/2
6/35
25.6 x 12.5
320.00 or 320
3500 ÷ 1,660
Round to the nearest tenths
2.1
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?
20 3/5 ÷ 4/8
Write your answer as a mixed number.
41 4/20 or 41 1/5
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.
55.318 ÷ 3.4
16.27
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
50 1/4 ÷ 20 4/5
Write your answer as a mixed number.
2 173/416
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)
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