Use Area Models to Multiply
19 × 18
342
27 × 34 = 27 × (30 + 4)
= (27 × 30) + (27 × 4)
= (20 + 7) × ____+ (20 + 7) × ____
= (20 × __) + (7 × ___) + (20 ×___) + (7 × ___)
= _____+ _____+ _____+ _____
=
30,4, 30, 30, 4, 4, 600, 210, 80, 28, 918
12 × 43
516
18 × 22
396
Seventy-two mushers compete in a sled-dog race. Each musher has 16 dogs. How many more dogs compete in the race than mushers?
1,080 more dogs
22 × 47 =
1,034
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
83 × 24
1,992
73 × 46
3,385
Thirteen students create a petition for longer recess. They need 5,000 signatures in all. So far, each student has 99 signatures. How many more signatures do they need?
3,713 signatures
13 × 19 =
247
38 × 31 =
1,178
59 × 76
4,484
38 × 65
2470
A farmer has 59 cows. Each cow produces 27 liters of milk. How many liters of milk do the cows produce in all?
1,593 liters
21 × 36 =
756
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)
Your friend finds 43 × 26. Is he correct? Explain.
143
× 26
248
+ 860
1,108
no; Your friend didn't add the regrouped ten to 248.
🮲5
× 🮲6
1 0 0
5 0
6 0
+ 3 0
🮲🮲🮲
1,1, 240
Each day, a cyclist bikes uphill for 17 miles and downhill for 18 miles. She drinks 32 fluid ounces of water after each bike ride. How many miles does the cyclist bike in 2 weeks?
490 miles
20 x 34 =
680
_____ × 36 = _____ × (3 + 6)
= (_____ × 30) + (_____ × 6)
= (20 + _____) × 30 + (20 + _____) × 6
= 20 × 30 + 6 × 30 + 20 × 6 + 6 × 6
= 600 + 180 + 120 + 36
= 936
26 × 36 = 936;
Line 1: 26; 26
Line 2: 26; 26
Line 3: 6; 6
When you use regrouping to multiply two-digit numbers, why does the second partial product always end in 0?
The product of 10s and 1s will give a 0 at the end.
Write the multiplication equation shown by the partial products.
3,200 + 120 + 560 + 21
47 × 83 = 3,901
A child ticket costs $14 less than an adult ticket. What is the total ticket cost for 18 adults and 37 children?
$2,617