Praxis Core Academic Skills for Educators: Mathematics (5733)Number and QuantityMedium
A carpenter is estimating the amount of wood needed. Each piece of wood is 1.75 meters long. If the carpenter needs 12 pieces, and each piece costs $3.50, what is the total length of wood needed in centimeters?
- A2.1 cm
- B210 cm
- C21 cm
- D2100 cm
Show answer & explanationAnswer & explanation
Correct answer: D. 2100 cm
First, calculate the total length in meters: 1.75 meters/piece * 12 pieces = 21 meters. Next, convert meters to centimeters. Since 1 meter = 100 centimeters, multiply the total meters by 100: 21 meters * 100 cm/meter = 2100 cm. The cost per piece is extraneous information.
Why the other options are wrong
- A. This might result from a significant calculation error or incorrect conversion factor.
- B. This might result from a calculation error, perhaps multiplying by 10 instead of 100 for conversion.
- C. This might result from miscalculating the total length or an incorrect conversion factor.
Unit Conversion (Meters to Centimeters)
To convert a length from meters to centimeters, multiply the value in meters by 100, as there are 100 centimeters in 1 meter.
- 1 meter (m) = 100 centimeters (cm).
- Conversion factor is 100.
- Used for expressing lengths in smaller units.
Memory trick: Meter to Centimeter, multiply by a hundred, make it grander!