Desi is looking at his calculator, which is shaped like a rectangular prism, and estimates it is about 3 in. wide, 4 in. tall, a
nd 12 in. thick. He wonders how many of these calculators he could fit in the trunk of his car, which is also roughly shaped like a rectangular prism, 4 ft wide, 3 ft deep, and 2 ft tall. His reasoning, shown here, contains an error. The calculator has a volume of about 60 in³, or about 6×101 in³.
The trunk of his car has a volume of about 41,472 in³, or about 4×104 in³.
4×1046×101=23×103 , so 667 calculators would fit in the trunk of his car.
What is Desi's error?
The value 41,472 should have been rounded to 4×105 .
The volume of the car's trunk is not about 41,472 in³.
We know that 1 ft = 12 in. The dimensions of the trunk of a car: 4 ft = 48 in wide, 3 ft = 36 in deep, 2 ft = 24 in tall. V = 48 * 36 * 24 = 41,472 in³ 41,472 in³ ≈ 4 * 10^4 in³ And the volume of the calculator: V ( calc. ) = 3 * 4 * 12 = 144 in³ Answer: Desi`s error is D ) The volume of the calculator is not about 60 in³.
Decimals are great for when you are dealing with money and want to round up, and fractions are used when baking (such as need 1/4 or a half cup of something)
