5-1Multiplying by 10 and 100/ 5-2 Multiplying by multiples of 10 and 100
5-3 Breaking apart to Multiply
5-4 Using Mental Math to Multiply
5-5 Using Rounding to estimate
5-6 Problem Solving Reasonableness
100
6 x 10=
What is 60?
100
What set of factors matches these partial products? 3 x 50=150 3 x 7=21 A 3 and 57 B 3 and 75 C 3 and 50 and 7 D 3 and 171
What is A?
100
5 x 17 Substitute 5 x ____ = 100 Adjust ____ -15 = _______
What is 20, 100, 85?
100
estimate the product 9 x 48
What is 450?
100
Barney has 7 pouches. Each pouch has 21 lego guys. About how many lego guys does Barney have? A 20 x 8 = 160 B 25 x 7 = 175 C 20 x 7 = 280 D 20 x 7 = 140
What is D?
200
Find the product and draw place value blocks to represent the answer. 7 x 100=
What is 700?
200
6 x 21=
What is 126?
200
6 x 104= hint: use compensation
What is 624?
200
estimate product 4 x 46 =
What is 200?
200
Abby has 9 photo albums. Each photo album has 99 photos. Which of the following shows a reasonable estimate of how many photos Abby has? A 7 x 125=875 B 8 x 110= 880 C 9 x 100 = 900 D 10 X 100 =1,000
What is C?
300
Part 1: What is the basic fact in 8 x 500? Part 2: Solve 8 x 500=
What is 8 x5=40 and 4,000?
300
5 x 216=
What is 1,080?
300
9 x 52=
What is 468?
300
At Coal City Intermediate School 115 fourth graders bought candy apples. Each fourth grader bought 6 candy apples. About how many candle apples did the fourth graders buy?
What is about 600 candy apples?
300
At an athletic club there are 11 people on a sports team. There are 8 teams. Is 88 people a reasonable answer? hint: estimate to check your math
What is yes, because my estimate of 10 x 8 =80, which is only 8 away from the exact answer of 88?
400
Without calculating the answer, tell which has the greater product. 8 x 400 or 40 x 8. Explain how you know.
What is 8 x 400 because it has 2 zero's in the product; 4 x 80 will only have 1 zero in the product?
400
Jordana is counting the books on 7 shelves. Each shelf has 148 books Which number sentence shows how to use breaking apart to solve this problem? A 148 + 7 B 148 - 7 C (7 x 1) + (7 x 4) + (7 x 8) D (7 x 100) + (7 x 40) + (7 x 8)
What is D?
400
Marissa and 3 friends bought tickets to the Goosebumps movie. The cost of each ticket with a bag of popcorn was $23. How much did their trip to the movies cost in all?
What is $92?
400
At Coal City Intermediate School 61 fifth graders bought candy apples. Each fifth grader bought 5 candy apples. About how many candle apples did the fifth graders buy?
What is about 300 candy apples?
400
Dylan has 7 soccer games. Each soccer game is about 34 miles from his home. Which of the following shows a reasonable answer of how many miles will Dylan travel if he goes to all 7 of his games? A 30 x 7 = 210 B 40 x 7 = 280 C 50 x 5 = 250 D 60 x 4 = 240
What is A?
500
A fourth grader breathes about 90 gallons of air per hour. Shana, a fourth grader arrives at school at 8:00 AM and leaves at 3:00 PM. How many gallons of air does she breathe at school? hint: 2 steps
What is 90x7=630 gallons?
500
Joey walked 5 miles every day for 37 days. Show breaking apart to find how many miles Joey walked in all.
What is (5 x 30) + (5 x 7) = 185 miles
500
The Coal City High School sold a total of 61 tickets for the play. Each ticket cost $8. How much money did they raise?
What is $488?
500
An adult female bald eagle has a wingspan that is about 7 feet long. How long would you estimate the female bald eagle's wing span in inches?
What is about 70 inches?
500
Every day for one week Aiden tells the class 11 jokes. Each joke took 3 minutes to tell. Aiden thinks that he told the class 33 minutes of jokes in one week. Explain why this answer is not reasonable.
What is Not reasonable because Aiden found the number of minutes he told for one day, not one week. To find the number of minutes of jokes he told in one week he would have to multiply 33 by 7, because there are 7 days in a week. 33 x 7 would be 231 jokes.
M
e
n
u