Multiply by 10s
90x10
900
42 × 14
400
26 × 31 =
806
28 × 47 = 28 × (40 + 7)
= (28 × 40) + (28 × 7)
= (20 + 8) × _____+ (20 + 8) × _____
= (20 × ___ ) + (8 × ____ ) + (20 × ____ ) + (8 × ____)
= ___+___ + ____+ ___
= So, 28 × 47 = ____ .
40, 7, 40, 40, 7, 7, 800, 320, 140, 56, 1,316, 1,316
26 × 17=
🬀
🬀
🬀
🬀
= ___
42, 140, 60, 200, 442
50x80
4,000
52 × 84
4,000
38 × 24 =
912
39 × 41 =
1,599
38 × 62=
= ____
6, 60, 480, 1,800, 2,356
10x76
760
57 × 81
4,800
22 × 47 =
1,034
74 × 12 =
888
36 × 93 =
3,348
_____ × 70 = 3,500
50
1,600
____×_____
| |
____ x ____= 1,600
39, 41
40, 40
You can type 19 words per minute. Your cousin can type 33 words per minute. How many more words can your cousin type in 15 minutes than you?
210 Words
Which expression does not belong with the other three?
(40 + 7) × 52
(40 + 7) × (50 + 2)
(40 × 7) × (50 × 2)
47 × (50 + 2)
(40 × 7) × (50 × 2)
57 × 22 =
1,254
The product of a number and twice that number is 800. What are the numbers?
You use 90 × 30 to estimate 92 × 34. Will your estimate be greater than or less than the actual product? Explain.
less than; 90 is less than 92, and 30 is less than 32.
Explain how to use an area model and partial products to multiply two-digit numbers.
Break apart both factors into tens and ones. Determine the partial products. Find the sum of the partial products.
An event coordinator orders 35 boxes of T-shirts to give away at a baseball game. There are 48 T-shirts in each box. If 2,134 fans attend the game, will each fan get a T-shirt?
no
How much greater is the product of 12 and 82 than the product of 11 and 82? Explain how you know without multiplying.
greater by 82; 12 × 82 = (11 × 82) + 82