# 4.5 Multiplicative Comparison and Measurement

## Unit Goals

• Students interpret, represent, and solve multiplicative comparison problems using an understanding of the relationship between multiplication and division. They use this thinking to convert units of measure within a given system from larger to smaller units.

### Section A Goals

• Analyze, describe, and represent multiplicative comparison situations.
• Solve one-step and two-step problems involving multiplicative comparison.

### Section B Goals

• Convert from larger units to smaller units within a given system of measurement.
• Solve multi-step problems involving multiplicative comparison and measurement.
• Understand the relative sizes of kilometers, meters and centimeters, liters and milliliters, kilograms and grams, and pounds and ounces.

### Section C Goals

• Solve multi-step problems involving multiplicative comparison and measurement.

### Glossary Entries

• common denominator
The same denominator in two or more fractions. For instance, $$\frac{1}{4}$$ and $$\frac{5}{4}$$ have a common denominator.

• composite number
A whole number with more than 1 factor pair.

• denominator
The bottom part of a fraction that tells how many equal parts the whole was partitioned into.

• equivalent fractions
Fractions that have the same size and describe the same point on the number line. For example, $$\frac{1}{2}$$ and $$\frac{2}{4}$$ are equivalent fractions.

• factor pair of a whole number
A pair of whole numbers that multiply to result in that number. For example, 5 and 4 are a factor pair of 20.

• mixed number
A number expressed as a whole number and a fraction less than 1.

• multiple of a number
The result of multiplying that number by a whole number. For example, 18 is a multiple of 3, because it is a result of multiplying 3 by 6.

• numerator

The top part of a fraction that tells how many of the equal parts are being described.

• prime number
A whole number that is greater than 1 and has exactly one factor pair: the number itself and 1.

• rounding

A formal way to say which number a given number is closer to. For example, for 182, the number 180 is the closest multiple of ten and 200 is the closest multiple of a hundred. We can round 182 to 180 (if rounding to the nearest ten) or 200 (if rounding to the nearest hundred).