Problem 1
Operation = Subtraction
Estimated answer = 8 dollars
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Explanation:
The regular price is estimated at $45, while the sale price is estimated at $37. The two subtract to get 45-37 = 8 dollars, which is about how much you save if you go for the discount price.
The actual amount saved is 45.32-36.50 = 8.82
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Problem 2
Operation = Division
Estimated answer = 75 cents
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Explanation:
$3.45 rounds to $3
Divide this over 4 to get 3/4 = 0.75, meaning each battery is 75 cents
The actual cost per battery is 3.45/4 = 0.86 dollars = 86 cents.
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Problem 3
Operation = Division
Estimated answer = $10
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Explanation:
Round $37.45 to the nearest ten to get $40; we could round to 37 but that's an oddball number in my opinion compared to 40. Plus 40 is divisible by 4, leading to 40/4 = 10. Each person chips in about 10 dollars.
The actual amount each person pays is 37.45/4 = 9.36
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Problem 4
Operation = Multiplication
Estimated answer = 180 miles
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Explanation:
18.75 rounds to 20, which we multiply by 9 to get 180
So the car can travel about 180 miles on 9 gallons. This is an overestimate because 18.75 rounded up to 20
The actual value is 18.75*9 = 168.75
