Vocabulary
What do you call a letter in an equation?
Example- n x 2=14
variable
What number is compatible with 23?
25
Estimate and Solve
33 x 46
30 x 50= 1500
80 x 30
2400
Mrs. Fesler brings each student in 4th grade 9 books to read. There are 38 students in 4th grade. How many books did Mrs. Fesler bring?
342 books
You multiply two numbers together to get a ________.
Example- 2 x 4 = 8
Product
8 is the product of 2 x 4
What number is compatible with 16?
15
Estimate and Solve
99 x 66
100 x 70 = 170
In the problem
52
x70
What is the first step?
Drop the zero!
Cameron washes 10 cars every day for 31 days. How many cars does he wash altogether?
310 cars
What do you call the numbers you multiply together to get a product?
Factors
Using compatible numbers, estimate 62 x 26.
60 x 25 = 1,500
True or False
90 x 20 is a good estimate using rounding for 92 x 28?
False!
28 should round to 30.
52 x 40
2080
Bralynn makes cookies for her 18 friends. If she makes each friend 12 cookies, how many cookies did she make?
216 cookies
What do you call it when you change a number to an easier number to multiply to make an estimate?
Compatible Number
Using compatible numbers, estimate 32 x 14.
30 x 15 = 450
Lyam scores 19 points in each basketball game. If he plays in 11 games, about how points will he score this season?
19 x 11 rounds to 20 x 10
about 200 points
31 x 90
2790
Colton goes on vacation. He visits 5 cities. In each city, he buys a 2 souvenirs. (One for each of his 4th grade teachers. Thanks, Colton!) If each souvenir cost $2, how much money does he spend?
$20
He buys 10 souvenirs (5 cities x 2 souvenirs =10).
10 x $2 = $20
The steps you take to solve a problem
Use compatible numbers to solve.
At East Elementary, there are 54 students in kindergarten. Mrs. Price buys each student a box of 24 crayons. About how many crayons does Mrs. Price buy?
25 x 50 = 1250
1250 crayons
Using rounding, what two numbers could you use to find an estimate of 1,400?
26 73 51 19
73 and 19
70 x 20 = 1400
45 x 22
1080
Mrs. Williams walks for 13 minutes a day and plays basketball for 32 minutes a day. If she does this everyday, how many minutes will she workout in 14 days?
630 minutes
Steps- 13 + 32= 45
45 x 14 = 630