Write an Expression
Write a numerical expression to represent the statement below, using parenthesis if needed.
To find 15 x 18, I double and halve.
30 x 9
Brad counted the number of balls in one layer of a box, and found out there were 24. The box has 9 layers. How many balls can the box hold in all? Show your work.
The box can hold 216 balls in all.
24 x 9 = (24 x 10) - (24 x 1) = 216
24 x 9 = (20 x 9) + (4 x 9) = 216
(9 x 2) x 5 =
90
Fill in the blank in the equation below. Then, describe how you can use number relationships to fill in the blank without having to find the answer to 16 x 14.
____ x 28 = 16 x 14
8 x 28 = 16 x 14
You can use doubling and halving. 28 is double 14 so you can cut 16 in half so both sides of the equation are equal.
Write a numerical expression to represent the statement below, using parenthesis if needed.
To find 9 x 26, I find 10 times 26 and subtract 1 group of 26.
(10 x 26) - (1 x 26)
For the problem below: show your work, explain how you handled the remainder, and write an equation to show your answer.
Four friends made 57 cookies and shared them equally. How many cookies did each friend get?
Each friend got 14 1/4 cookies.
You can split the cookie into fourths.
57 ÷ 4 = 14 1/4
5 x (13 x 2) =
130
Determine if the equation is true or false. Then, describe how you can use number relationships to tell whether the equation is true or false without having to find the answer on both sides.
18 x 120 = 9 x 240
True because of the doubling and halving strategy
Write a numerical expression to represent the statement below, using parenthesis if needed.
How can I find the volume of a box that has a 18-by-21 base and 31 layers
18 x 21 x 37
For the problem below: show your work, explain how you handled the remainder, and write an equation to show your answer.
There are 57 kids in the After-School Club. Tomorrow they are going to the park. If each car can carry 4 kids, how many cars will they need to get to the park?
They will need 15 cars.
57 ÷ 4 = 14 R 1
14 cars would carry 56 kids, so another car is needed to carry all 57 kids.
50 x 64 - (1 x 64)
3,136
Determine if the equation is true or false. Then, describe how you can use number relationships to tell whether the equation is true or false without having to find the answer on both sides.
(3 x 4) x 6 = 3 x (4 x 6)
True. You can multiply numbers in any order and the answer will be the same.
Write and solve an equation to represent the statement below:
To find 15 times 32, I multiply 10 times 32 and add it to 5 times 32.
(10 x 32) + (5 x 32) = 320 + 160 = 480
For the problem below: show your work, explain how you handled the remainder, and write an equation to show your answer.
Andrew paid $57.00 for 4 super-size pizzas. How much did each pizza cost?
Each pizza cost $14.25
You can split the remaining dollar into fourths, or quarters.
57 ÷ 4 = 14.25
2 x (6 x 4) + 2 x (3 x 4) + 2 x (6 x 3) =
108
Determine if the equation is true or false. Then, describe how you can use number relationships to tell whether the equation is true or false without having to find the answer on both sides. If it is false, fix the equation.
58 x 17 = (60 x 17) + (2 x 17)
False. 50 does not equal 60 + 2.
58 x 17 = (60 x 17) - (2 x 17)
Write and solve an equation to represent the statement below:
To find 42 times 25, I double and halve.
42 x 25 = 21 x 50 = 1,050
How many 1 x 1 x 1 cubes are in a rectangular prism that is 6 cubes wide, 2 cubes long, and 5 cubes tall?
2 x 6 x 5 = 60 cubes
Fill in the blank to make the equation true.
(99 x 497) + (1 x 497) = ____ x 497 = ____
(99 x 497) + (1 x 497) = 100 x 497 = 49,700
Fill in the blanks to make the equation true.
98 x 36 = (___ x 36) - (2 x 36) = ____
98 x 36 = (100 x 36) - (2 x 36) = 3,528