Evaluate Expressions
Evaluate:
6 × (8 × 2)
96
120 × 15 = 6 × _____
What belongs in the blank?
300
A rectangular prism has:
What is the volume?
There are 72 students going on a field trip.
Each bus holds 12 students.
How many buses are needed?
6 buses
A student says:
4 × (6 + 2) = 26
True or false?
(9 × 2) × 5
90
Without solving the entire problem, explain how you could use a known fact to solve:
25 × 16
Hint:
Think about doubling and halving.
50 x 8 = 400
A prism has 24 cubes on each layer and 6 layers.
What is the volume?
144 cubic units
A teacher has 7 boxes of pencils.
Each box has 24 pencils.
She gives away 10 pencils.
Write an expression and solve.
(7 × 24) − 10
Answer: 158 pencils
A student writes:
5 × (10 − 2) = 48
Find the mistake.
5 × 8 = 40
(40 × 25) − (2 × 25)
950
Which would be easier to solve?
49 × 10 − 49
OR
49 × 9
Explain why they are related.
441
A rectangular prism has:
8 × 5 × 7
What does each number represent?
8 = length
5= width
7 = height (# of layers)
A school has 96 students.
Each van holds 15 people.
How many vans are needed?
96 ÷ 15 = 6 remainder 6
But the answer is 7 vans.
I have a number.
My expression is:
(6 × 7) + 8
What is my number?
50
2 × (4 × 5) + 3 × (6 × 2)
76
Your teacher says:
“To solve 36 × 25, I can double 36 and halve 25.”
Is she correct?
Show why.
36 × 25 = 72 × 12 = 864
A rectangular prism contains 216 cubes.
Each layer contains 27 cubes.
How many layers are there?
8 layers
A bakery makes 396 cupcakes.
Each tray holds 33 cupcakes.
How many trays are needed?
396 ÷ 33 = 12 trays
Which expression is different?
A. 4 × 25
B. 100 ÷ 1
C. 2 × 50
D. (5 × 20) + 10
D
I am thinking of a number.
My expression is:
3 × (8 + 4) − 5
What is my answer?
31
No calculator. No traditional multiplication allowed!
Solve:
48 × 25
You must explain your strategy.
Possible strategy:
48 × 100 ÷ 4 = 1,200
A rectangular prism has a volume of 360 cubic units.
Its base is:
10 units × 6 units
How many layers does it have?
6 layers
A teacher has $75 to buy identical notebooks for 4 students.
Can she spend exactly $75?
Write the expression.
75 ÷ 4 = $18 remainder $3
(8 × 25) + (4 × 10) − 15
Teams must:
200 + 40 − 15 = 225