Powers of 10
12 x 104
120,000
Find a reasonable estimate for 7 x 396 using rounding or compatible numbers. Be ready to explain how you rounded.
Some possible answers:
5 x 400 = 2,000
10 x 400 = 4,000
76
x 59
4,484
A store received a shipment of 37 TVs valued at $625 each. Write and solve an equation, using v to show the value of the whole shipment.
v= 37 x 625
v= $23,125
Morgan makes $10 per hour babysitting. If she babysits for 17 hours in October, how much money will she make?
17 x 10 = $170
102 x 39
3,900
Find a reasonable estimate for 256 x 54 using rounding or compatible numbers. Be ready to explain how you rounded.
Possible answers:
250 x 50 = 12,500
300 x 50 = 15,000
47 x 302
14,194
Maisy saved $1,250 last year.
Kaleigh saved 7 times as much.
Write and solve an equation using k to show how much money Kaleigh saved.
k=1,250 x 7
k=$8,750
Balloons come in packs of 12. If the student council blows up all of the balloons in 18 packs for the Fall Ball, how many balloons did they blow up?
12 x 18 = 216 balloons
20 x 1,000
20,000
Rome estimated the product of 83 x 54 by finding that 80 x 50 = 4,000.
Did he overestimate or underestimate? How do you know? Would the actual answer be greater or less than 4,000?
Underestimated- he rounded both factors to lower numbers. The actual answer would be greater than 4,000 because the actual factors are greater than the estimated numbers.
7,133
x 4
28,532
If Gianna's family spend $985 per month on their rent, how much money do they spend on rent in a year?
12 x 985 = $11,820
At the movies, popcorn costs $8. If 104 containers of popcorn are sold each month, how much are the monthly popcorn sales?
$8 x 10,000 = $80,000
Which would be a more accurate estimate for 45 x 806:
45 x 800 or 40 x 800
How do you know?
45 x 800 because only one of the factors was changed and 800 is the same in both estimates.
604 x 55
33,220
Student council wants to have a Pizza Day incentive. 532 students will be participating. If there are 8 slices in each pizza, and the school orders 58 pizzas, will there be enough for each student to get a slice? Use estimation to explain.
No because 60 x 8 = 480. I overestimated and the product is still less than the amount needed.