to exchange amounts of equal value to rename a number
regroup
100
Kevin bought 30 packs of baseball cards. There are 12 cards in each pack. How many cards did Kevin buy?
360 cards.
100
A half dollar has a diameter of about 31 millimeters. About how many millimeters long would a row of 56 half-dollars be?
about 1,800 millimeters
100
Owners of a summer camp are buying new cots for their cabins. There are 16 cabins. Each cabin needs 6 cots. Each cot costs $92. How much will the new cots cost?
$8,832
100
Darren hiked 16 miles each day on a 12-day hiking trip. Angel hiked 14 miles each day on her 16-day hiking trip. In all, how many more miles did Angel hike than Darren?
32 miles.
200
numbers that are easy to compute with mentally
compatible numbers
200
The Lin family drove 50 hours to a vacation spot. They drove an average of 48 miles each hour. How many miles did they drive?
2,400 miles.
200
Jolina burns 93 calories each time she plays fetch with her dog. She plays fetch with her dog once a day. About how many calories will Jolina burn playing fetch with her dog in 28 days?
about 2,700 calories
200
A theater has 28 rows of 38 seats downstairs and 14 rows of 26 seats upstairs. How many seats does the theater have?
1,428 seats.
200
There are 48 crayons in a box. There are 12 boxes in a carton. Mrs. Fitzgerald ordered 6 cartons of crayons for the school. How many crayons did she get?
3,456 crayons.
300
a method of multiplying in which the ones, tens, hundreds, and so on are multiplied separately and then the products are added together
partial products
300
Janice packs 12 jars of jam in a box. She has 40 boxes. She has 542 jars of jam. How many jars of jam will she have left when all the boxes are full?
62 jars.
300
Mr. Riese jogs for 35 minutes each day. He jogs 5 days in week 1, 6 days in week 2, and 7 days in week 3. About how many minutes does he jog?
about 700 minutes.
300
A choir needs new robes for each of its 46 singers. Each robe costs $32. What will be the total cost for all 46 robes?
$1,472
300
Irence is having a party on Saturday. She buys 17 bags of candy with 85 pieces of airheads in each. She also buys 15 bags of candy with 90 starbursts in each. How many more airheads than starbursts did she buy?
95 more.
400
the property that states that when the grouping of factors is changed, the product remains the same
Associative property of multiplication
400
For the school play, 60 rows of chairs are set up. There are 22 chairs in each row. How many chairs are there?
1,320 chairs
400
There are 48 beads in a package. Fiona Liu bought 4 packages of blue, 9 packages of gold, 6 packages of red, and 2 packages of silver beads. About how many beads did Fiona Liu buy?
about 1,000 beads.
400
A basketball team scored an average of 52 points in each of 15 games. Based on the average, how many points did the team score in all.
780 points.
400
On each of Selina's bird-watching trips, she has seen at least 24 birds. If she has takes 4 of these trips each year over the next 16 years, at least how many birds has Selina seen?
at least 1,536 birds.
500
the property that states when the order of two factors is changed, the product remains the same
commutative property of multiplication
500
At West School, there are 80 classrooms. Each classroom has 44 students. How many students are at West School?
3,520 students.
500
On average, a refrigerator door is opened 38 times each day. Daniel has two refrigerators in his house. Based on this average, about how many times in a 3-week period are the refrigerator doors opened?
about 1,600 times.
500
Kevin collected stamps. He counted 48 pages in his collector's album. The first 20 pages each have 35 stamps. The rest of the pages each have 54 stamps. How many stamps does Kevin have in his album?
2,212
500
A school is adding 5 rows of seats to the auditorium. There are 5 seats in each row. Each new seat costs $99. What is the total cost for the new seats?