Multiply Multiples
JP built 10 Lego sets. If each set has 90 Lego pieces in it, how many Legos did JP use in total?
JP has 900 Legos.
Estimate the product:
62 x 125
Round 125 to 100 and 62 to 60:
60 x 100 = 6,000
Show your work to solve 34 x 51. Name your strategy.
1,734
Thomas as 45 display cases. Each case has 16 collectible items. How many collectible items does Thomas have?
Thomas has 720 collectible items.
Round 98,732 to the ten thousands place.
99,000
Jovi had 40 boxes of cupcakes. Each box has 20 cupcakes in it. How many cupcakes does Jovi have?
Jovi has 800 cupcakes.
Estimate the product:
89 x 62
Round 89 to 90 and 62 to 60:
90 x 60 = 5,400
Show your work to solve 73 x 81. Name your strategy.
5,913
Logan owns 92 pet shops. Each pet shop has 38 employees. How many employees work for Logan in total?
Logan has 3,496 employees.
A total of 103,985 fans attended the baseball game on Saturday, and a total of 103,667 fans attended the game on Sunday. Use > or < to compare the attendances. Which day had more fans attend the game? Which place value should you use to compare?
103,985 > 103,667
Use the hundreds place to compare.
The product of two factors is 4,800. If one of the factors is 80, what is the other factor? Explain.
60. I know this because 80 x 60 = 4,800.
Dmitri went apple picking with 18 family members. If each person picked 26 apples, about how many apples did they pick all together?
Round 18 to 20 and 26 to 30:
20 x 30 = 600
Dmitri’s family picks about 600 apples.
Show your work to solve 13 x 62. Name your strategy.
806
Brooke bought a new rug for her home. The rug is 73 inches by 75 inches. What is the area of the rug?
The rug is 5,475 square inches.
There are 17,000 people registered for a dance marathon. 10,730 people registered to volunteer and not dance. How many people registered to dance?
17,000 – 10,730 = 6,270
6,270 people registered to dance.
Bob says 50 x 400 = 200. Explain his error.
Bob forgot to add two zeroes into his answer. 4 x 5 = 20, so his answer should have an extra zero in addition to three zeroes in the factors.
Bob estimates the product of 211 and 60 is 1,800. Is this estimate reasonable? Explain.
No it is not reasonable. I know this because 211 should be rounded to 200, then multiplied by 60 to get 12,000 not 1,800.
Show your work to solve 19 x 24. Name your strategy.
456
Lucas ran 11 laps 10 times in July. He ran 13 laps 15 times in August. How many laps did Lucas run during the two months.
July: 110 laps total
August: 195 laps total
Total: 295 laps
What are the first 5 multiples of 15?
15, 30, 45, 60, 75
Amusement Park tickets cost $40 for each adult and $30 for each child. If 90 girls and 40 adults visit the park, how much will the trip cost?
Girl’s Cost: 90 x $30 = $2,700
Adult’s Cost: 40 x $40 = $1,600
Total Cost: $2,700 + $1,600 = $4,300
Wind turbines generate large amounts of electricity from wind energy. The blades on a wind turbine can revolve 22 times per minute. If a wind turbine runs for 1 hour, about how many times do the blades revolve? Remember, there are 60 minutes in one hour.
About 1,200 times.
Show your work to solve 41 x 77. Name your strategy.
3,157
Tony says to multiple 219 x 30, you multiply 2 x 30, 1 x 30, and 9 x 30 and then add the partial products. Explain Tony’s error. How would you help Tony understand how to correctly multiply 219 x 30?
Tony did not use the correct place value for each digit when he expanded 219. He would need to do 200 x 30, 10 x 30, and 9 x 30. I could use place value blocks to show Tony how to use place value.
What are the factors of 36?
1, 2, 3, 6, 12, 18, 36