VOCABULARY
A number close to an exact amount or to find about how many or how much
Estimate
Solve:
7 x 7,639
53,473
What is the missing factor: 80 x _____ = 4,000 ?
50
Estimate 32 x 26
900 or 750
The students in the Go Green club started a school recycling program. In September, the students collected 86 pounds of paper. For October, their goal is to collect 3 times the amount of paper they collected in September. If the club meets its goal, how many total pounds of paper will the students collect in October?
258 pounds of paper
The answer to a multiplication equation or expression
Product
Use the partial products to solve:
59 x 34
2,006
A store kept track of how many t-shirts they sold in 1 year. They sold 18,432 t-shirts with the saying “I Love Tacos” and 34,563 t-shirts with the saying “I love Pizza”. How many t-shirts did they sell in total?
52,995 t-shirts
Estimate 96 x 82
100 x 80 = 8,000
Youssef has 18 bags of coins. Each bag has 17 nickels, 6 pennies, and 16 dimes. How many coins does Youssef have in total?
702 coins
The numbers multiplied together to get a product.
Factors
True or False:
14 x 25 ≠ 360
JUSTIFY YOUR ANSWER!
True
Correct Answer: 350
Compare using <, >, =
Twenty-five thousand four hundred twenty ________ 25,421
Twenty-five thousand four hundred twenty < 25,421
Ms. Ortoli has 16 bags of 42 cookies. Ms. Tague has 12 bags of 32 cookies. About how many cookies does Mrs. Ortoli have than Ms. Tague?
16 x 42 -> 20 x 40 = 800
12 x 32 -> 10 x 30 = 300
800-300 = about 500 more cookies
Manny has 3 rose bushes in his front yard. There are 8 more rose bushes in his backyard. He gave each bush 12 spoonfuls of plant food. How much plant food did Manny use altogether?
132 spoonfuls
The product of the ones, or tens, or hundreds, and so on in mult-idigit multiplication when we decompose the number into parts.
Partial Products
Use STANDARD ALGORITHM to solve this expression
42 x 63
2,646
Mr. Carty wrote the number 287,549 on the board. Write a number where the value of the digit 4 is 10 times greater than the value of the digit 4 in Mr. Carty’s number.
Examples:
287,459
366,467
5,478
431
46 x 66 = 35,456
Is the answer above reasonable? Why or why not?
The answer is NOT reasonable because 46 x 66 to be about 3,500 which is not close to 35,456
50 x 70 = 3,500
Perry is a nurse who works 35 hours a week. There are 52 weeks in a year, but he takes 3 weeks off each year for vacation. How many hours does Perry work each year?
1,715 hours
This property is when you change the order of the factors, but the product remains the same.
Example: 25 x 42 or 42 x 25
Commutative Property
26 x 34 <, >, or = 37 x 22
26 x 34 = 884
37 x 22 = 814
884 > 814
Last Friday, students at Frost Elementary could choose between hot dogs and hamburgers. There were 45 more students who bought hamburgers than hot dogs. If 78 students bought hot dogs and hot dogs cost $2 and hamburgers $3, how much money was made in all?
$525
Explain how you could use estimation to decide which has the greater product:
39 x 21
32 x 32
32 x 32 can be estimated to about 900 and 39 x 21 can be estimated to be about 800.
32 x 32 would have the greater product.
Aiden has 8 boxes of food his friends and family made to donate to those in need. Each box contains 29 packs of rice, 82 bottles of water, 78 cans of food, and 102 heating packets. How many items does he have to donate in total?
2,328 items