Using Unit Multipliers to Convert Measures
Using Unit Multipliers to Convert Measures is a Grade 7-8 math skill that teaches students to convert between units of measurement by multiplying by conversion factors (unit multipliers) equal to 1. This dimensional analysis approach works for length, weight, capacity, and even compound units.
Key Concepts
New Concept A unit multiplier is a ratio in which the numerator and denominator are equivalent measures but different units. Since 12 inches equal one foot, we can write these two unit multipliers for that relationship. $$\frac{12 \text{ in.}}{1 \text{ ft}} \quad \text{and} \quad \frac{1 \text{ ft}}{12 \text{ in.}}$$ What’s next Next, we'll apply this tool to convert length, time, and volume, and even tackle mixed units like feet and inches.
Common Questions
What is a unit multiplier?
A unit multiplier is a fraction equal to 1 that has different units in the numerator and denominator. Multiplying by it converts a measurement without changing the quantity.
How do you use unit multipliers to convert units?
Write the original measurement, then multiply by a fraction where the desired unit is on top and the original unit is on the bottom. The original units cancel out, leaving the new unit.
What is an example of using a unit multiplier?
To convert 3 feet to inches: 3 feet times (12 inches / 1 foot) = 36 inches. The feet cancel and inches remain.
Can unit multipliers be used for compound units like speed?
Yes, you can chain multiple unit multipliers to convert compound units. For example, to convert miles per hour to feet per second, use two multipliers.
What grade covers unit multipliers for conversion?
Unit multipliers are taught in Grade 7 and Grade 8 math, and also used in science classes.