Multi-Digit Multiplication — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A Grade 5 assembly seats 24 students per row in 18 rows. Three more rows of 24 are added. How many students fit?
A) 432 students
B) 504 students
C) 456 students
D) 480 students
18 rows plus 3 new rows is 21 rows. Then 21 times 24 equals 504 students. Grade 5 students check magnitude: about 20 times 25 is 500, close to 504.
2. A factory packs 48 markers per box and 25 boxes per case. How many markers are in 6 cases?
A) 7,000 markers
B) 7,200 markers
C) 1,200 markers
D) 6,800 markers
48 times 25 equals 1200 markers per case. Then 1200 times 6 equals 7200 markers. The Grade 5 magnitude check estimates 50 times 25 times 6, near 7500.
3. A bus drives 65 miles per hour for 4 hours each day for 12 days. Total miles driven?
A) 3,120 miles
B) 780 miles
C) 260 miles
D) 3,360 miles
65 times 4 equals 260 miles per day. Then 260 times 12 equals 3120 miles. Grade 5 students verify by partial products: 260 times 10 plus 260 times 2 equals 2600 plus 520.
4. A Grade 5 class collects 36 cans per student. With 27 students and a bonus of 150 cans, how many total cans?
A) 972 cans
B) 1,150 cans
C) 1,122 cans
D) 1,022 cans
36 times 27 equals 972 cans from students. Adding the 150-can bonus gives 1122 total cans. Grade 5 magnitude check: about 35 times 27 plus 150 is near 1100.
Part B: Fill in the Blank
Write the correct answer on each line.
1. Grade 5 trip: 14 buses each carry 52 students. Total students transported is 728.
14 times 52 equals 728 students. Using partial products, 10 times 52 is 520 and 4 times 52 is 208, summing to 728 for Grade 5 verification.
2. A bakery sells 36 muffins per tray and uses 45 trays daily. Daily muffin total is 1620.
36 times 45: 30 times 45 is 1350 and 6 times 45 is 270. Adding gives 1620 muffins, the daily Grade 5 total for the bakery.
3. A car uses 28 gallons in a week. In 16 weeks it uses 448 gallons.
28 times 16 equals 448 gallons. Grade 5 students may use 28 times 10 plus 28 times 6, which is 280 plus 168, confirming the total of 448 gallons.
4. A school assembles 32 packets each containing 24 sheets, plus 50 extra sheets. Total sheets is 818.
32 times 24 equals 768 sheets in packets. Adding 50 extra sheets gives 818 total. Grade 5 magnitude check: 30 times 25 plus 50 is near 800.
5. A Grade 5 walk-a-thon has 18 students each walking 25 laps of 60 yards. Total yards walked is 27000.
25 laps times 60 yards equals 1500 yards per student. Then 18 students times 1500 yards gives 27000 yards walked for the Grade 5 walk-a-thon total.