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Multiply by Tens
Estimate Products
Distributive Property
Partial Products and Algorithm
Math Vocab
100
12 x 70
What is 840?
100
For 21 x 14, is the estimate GREATER THAN or LESS THAN the actual answer?
What is LESS THAN? 21 x 14 rounds to 20 x 10, which is 200. 200 is less than the actual answer, 294
100
Find 13 x 15
METHOD ONE: (10 + 3) x 15 = (15 x 10) + (15 x 3) = 150 + 45 = 195 METHOD TWO: 13 x (10 + 5) = (13 x 10) + (13 x 5) = 130 + 65 = 195
100
Find 19 x 15
PARTIAL PRODUCT: 100 + 90 + 50 + 45 = 285 ALGORITHM: 19 x 15 = 95 + 190 = 285
100
24 x 57 = 24 x (50 + 7) = (24 x 50) + (24 x 7) Associative, Commutative, or Distributive Property?
What is Distributive Property?
200
80 x 80
What is 6,400?
200
25 x 28. Is the estimate GREATER THAN or LESS THAN the actual product?
What is GREATER THAN? 25 x 28 rounds to 30 x 30, which is 900. 900 is greater than the actual answer, 700.
200
Find 11 x 52
METHOD 1: (10 + 1) x 52 = (52 x 10) + (52 x 1) = 520 + 52 = 572 METHOD 2: 11 x (50 +2) = (11 x 50) + (11 x 2) = 550 + 22 = 572
200
Find 54 x 51
PARTIAL PRODUCT: 2,500 + 200 + 50 + 4 = 2,754 ALGORITHM: 54 x 51 = 54 + 2700 = 2754
200
30 x 20 = 30 x (10 x 2) = (30 x 10) x 2 Associative, Commutative, or Distributive Property?
What is Associative Property?
300
45 x 50
What is 2,250?
300
Estimate 73 x 84
What is 5,600? 73 x 84 rounds to 70 x 80, which is 5,600
300
Find 47 x 19
METHOD ONE: 47 x (10 + 9) = (47 x 10) + (47 x 9) = 470 + 423 = 893 METHOD TWO: (40 + 7) x 19 = (19 x 40) + (19 x 7) = 760 + 133 = 893
300
Find 64 x 46
PARTIAL PRODUCT: 2400 + 360 + 160 + 24 = 2,944 ALGORITHM: 64 x 46 = 384 + 2560 = 2,944
300
24 x 57 = 57 x 24 Associative, Commutative, or Distributive Property?
What is Commutative Property?
400
69 x 80
What is 5,520?
400
Find the variable "a" in: 40 x a = 2,400
What is a = 60? 40 x 60 = 2,400
400
Find 73 x 34
METHOD ONE: (70 + 3) x 34 = (34 x 70) + (34 x 3) = 2,380 +102 = 2,482 METHOD TWO: 73 x (30 + 4) = (73 x 30) + (73 x 4) = 2190 + 292 = 2,482
400
Find 99 x 99
PARTIAL PRODUCT: 8,100 + 810 + 810 + 81 = 9,801 ALGORITHM: 99 x 99 = 891 + 8,910 = 9,801
400
The word "about" (like in: "about how many....") tell you to ___________, as in round both numbers before multiplying.
What is estimate?
500
99 x 90
What is 8,910?
500
Sienna and Olivia create 16 paintings together each month. ABOUT how many paintings will they create in 3 years?
What is 800 paintings? 16 x 36 rounds to 20 x 40, which is 800
500
Find 99 x 98
METHOD ONE: (90 + 9) x 98 = (98 x 90) + (98 x 9) = 8,820 + 882 = 9,702 METHOD TWO: 99 x (90 + 8) = (99 x 90) + (99 X 8) = 8,910 + 792 = 9,702
500
Many of the boys in Mrs. Faherty's class play sports 25 days out of each month. How many days would they have played at the end of three years? (Yes, including Christmas, Easter, and Summer breaks)
PARTIAL PRODUCT: 600 + 120 + 150 + 30 = 900 days ALGORITHM: 25 x 36 = 150 + 750 = 900 days
500
A multiplication method in which the products of each place value are found separately, and them added together
What is partial product?