Vocabulary
What are the numbers called when we multiply them together?
Factors
No, it is not reasonable.
Solve:
11
x 2
Answer: 22
Solve: (1x3)x2 = 1x(3x2)
What is area?
The amount of space inside a flat object.
54 cupcakes and 68 muffins were ready at the bakery. Is reasonable to say that 135 people could buy an item at the bakery?
No, it is not reasonable.
Solve:
12
x 3
Answer: 36
4 square units x 7 square units
28 square units
Solve: (2x4)x2 = 2x(4x2)
Answer: 16
What is reasonableness?
If the answer makes sense based on the problem.
There were 77 Eagles fans and 86 Giants fans. Is it reasonable to say that the sports store should have 170 footballs? Explain.
Yes, it is reasonable. My estimated answer and the real answer are close to 170. It makes sense based on the problem.
Estimated Answer: 77 rounds up to 80. 86 rounds up to 90. 80+90=170 footballs.
Real Answer: 77+86=163
Solve:
22
x 3
Answer: 66
5 cm x 8 cm
40 square cm
Solve: (4x3)x2 = 4x(3x2)
Answer: 24
What is a square unit?
A tiny square used to measure area by counting how many fit inside a shape.
There are 122 3rd graders and 105 4th graders at the field day. Is it reasonable to say that there should be 235 water bottles?
Yes, it is reasonable. My estimated answer and the real answer are close to 235. It makes sense based on the problem.
Estimated Answer: 122 rounds down to 120. 105 rounds up to 110. 120+110=230 water bottles.
Real Answer: 122+105=227
Solve:
34
x 4
Answer: 136
Length: 7 inches
Width: 3 inches
21 square inches
Solve: (4x3)x5 = 4x(3x5)
Answer: 60
What does the Associative Property of Multiplication mean?
When you are multiplying 3 factors, you can group them in different ways and you will always get the same product.
265 people came to the car shop last week. 523 people came to the car shop this week. Is it reasonable to say that 700 went to the car shop in both weeks?
No, it is not reasonable. My estimated answer and the real answer are not close to 700.
Estimated Answer: 265 rounds up to 300. 523 rounds to 500. 300+500=800 water bottles.
Real Answer: 265+523=788 people
Solve:
46
x 5
Answer: 230
Length: 9 cm
Width: 6 cm
54 square cm
Solve: (6x4)x5 = 6x(4x5)
Answer: 120