Powers of 10
85 x 103
85,000
Estimate the product:
19 x 513
20 x 500=10,000
1,562
A school district is replacing all of the desks in the classrooms. There are 103 classrooms and each classroom has 24 new desks. How many desks will the school district need to buy?
103 x 24= 2,472 desks
Solve:
360 x 48=
17, 280
Choose all the expressions that are equal to 5,600.
a. 56x102
b. 56x103
c. 56x104
d.100x56
e. 1,000x56
a. 56x102
d. 100x56
Estimate the product:
42 x 598=
40 x 600=24,000
Find the product of 157x24.
3,768
There are 36 large fish tanks at the zoo. Each tank holds 205 gallons of water. How many gallons of water would it take to fill the tanks?
205x36=7,380 gallons
Find the product:
132 x 16=
2,112
Solve:
12x100
12
A musical is playing at a theater that has 628 seats. Which is the best estimate of the total number of tickets available for 33 shows?
a. 500x30
b. 600x30
c. 600x50
d. 700x40
b. 600x30
Solve:
806 x 20=
16,120
A furniture manufacturer shipped 35 cartons to a store. Each carton weighed 255 pounds. What was the total weight of the cartons?
Show a bar diagram.
35x255=8,925 pounds
Solve:
999 x 999=
998, 001
Tell yes or no to see if the number 102 makes the equation true.
a. 39 x ____=390
b. 4 x _____=400
c. 20 x _____=200
a. no
b. yes
c. no
Lance has 102 packages of sports cards. Each package has 28 cards. Use rounding to estimate. About how many cards does Lance have?
100 x 30=3,000 cards
Find the product of 338x45.
15,210
Josh ordered 1,029 baseball cards. Kristyn ordered 5 times as many cards as Josh. Write and solve an equation to find b, the number of baseball cards Kristyn ordered.
1,029x5=b;
b=5,145
There are 25 cans of mixed nuts. If each can has 340 nuts, what is the total number of nuts, n, in all cans? Write and solve an equation for n.
25x340=n; n=8,500
The weight of an elephant is 103 times the weight of a cat. If the elephant weighs 14,000 pounds, how many pounds does the cat weigh?
14
Since 3 zeros were annexed to find the product, work backward and remove the three zeros.
At a warehouse, 127 delivery trucks were loaded with 48 packages on each truck. Estimate the total number of packages on the trucks. Write an equation to model your work.
50x130=6,500 packages
Solve:
384 x 295=
113,280
Maria needs a trombone for only 12 months. Renting the trombone costs $34 per month. She can buy the trombone fo $495. Should she buy ore rent? Explain. How much will she pay?
Rent; since she only needs the trombone for 12 months, 12 x $34=$408, and $408 < $495.
Ted's sales goal for this month is $6,000. Ted sells 289 tickets for $16 each. He says, "since 300x20=$6,000, I made my sales goal." Do you agree with Ted? Explain.
No, Since Ted rounded 289 to 300 and 16 to 20, he found an overestimate. So the actual sales are less than $6,000.