Mental Math
What is the product of 7 × 60?
420
Break apart 143 into place values/ expanded form.
100 + 40 +3
Which expression is equal to 4 × 125?
A. (4 × 100) + (4 × 20) + (4 × 5)
B. 4 + 125
C. (4 × 100) + 25
D. 4 × 100 + 20 + 5
A
A bakery sells 28 boxes of cupcakes. Each box has 6 cupcakes. How many cupcakes were sold?
28 x 6 = 168 cupcakes
Estimate the product of 4 × 387 by rounding 387 to the nearest hundred.
4 x 400 = 1,600
What is the product of 9 x 90
810
Solve 143 × 3 using partial products or the area model.
100 x 3 = 300
40 x3 =120
3 x3= 9
300+120+9=
429
Which expression is equivalent to (500 × 3) + (42 × 3)?
A. 500 × 42
B. 542 × 3
C. 500 × 6
D. 542 + 3
B
A library has 4 shelves with 123 books on each shelf. How many books are there altogether?
4 x 123= 492 books
A parent wants to buy 3 computers costing $398 each. They estimate the total will be about $1,200. Is this reasonable? Explain.
Yes. Round $398 to $400. Then 3 × $400 = $1,200. The exact total is $1,194
What is the product of 500 x 9?
4,000
Select all the partial products for 2,142 × 3.
A. 6,000
B. 300
C. 400
D. 120
E. 6
A, C, D, E (6,000; 400; 120; 6).
Select all expressions that have a product of 840.
A. 105 × 8
B. (800 + 40) × 1
C. 7 × 120
D. (8 × 100) + (4 × 10)
E. 84 × 100
A, B, C, D
A deli sells 245 turkey sandwiches in one month. If it sells the same number for 4 months, how many turkey sandwiches will it sell?
245 x 4 = 680 sandwiches
Which expression has the same value as 5 × 163?
A. (5 × 100) + (5 × 60) + (5 × 3)
B. (5 × 1) + (5 × 6) + (5 × 3)
C. (5 × 100) + (5 × 6) + (5 × 3)
D. 5 + 163
A
Use compensation to solve 21 x 4 (use a friendly number)
20 x 4= 80
80+4= 84
Draw an area model or use partial products to solve 326 × 4.
1,304
Which expressions are equivalent to 936? Select all that apply.
A. 117 × 8
B. 8 × 117
C. (100 × 8) + (10 × 8) + (7 × 8)
D. 9 × 136
E. (8 × 100) + (8 × 17)
A, B, C, E
A pizza shop makes 235 pizzas and 68 subs every day. How many total items does the shop make in 4 days?
(235 + 68) × 4 = 303 × 4 = 1,212 items
A school orders 7 boxes of pencils. Each box contains 389 pencils. Estimate how many pencils the school ordered by rounding to the nearest hundred.
7 X 400 = 2,800 pencils
Use compensation to solve 6 × 19. (Find a friendly number)
6 x 20 = 120
120 − 6 = 114
Solve using area model or partial products
3,215 × 4
12,000+ 800+ 40+ 20= 12,860.
A student says that 6 × 248 is the same as (6 × 200) + (6 × 40) + (6 × 8). Is the student correct? Explain and find the product.
Yes. The student used the distributive property to break apart 248. The product is 1,488.
A school buys 3 laptops costing $1,248 each and 3 tablets costing $396 each. What is the total cost? Show an equation
(3 × 1,248) + (3 × 396) = 3,744 + 1,188 = $4,932.
A deli sells 186 roast beef sandwiches in one month. It sells 3 times as many tuna sandwiches as roast beef sandwiches each month. How many more tuna sandwiches than roast beef sandwiches are sold over 4 months?
186 × 3 = 558 tuna sandwiches per month.
The difference each month is 558 − 186 = 372.
Over 4 months: 372 × 4 = 1,488 more tuna sandwiches.