Unit rate word problem: Which is a better buy?
I show you TWO ways to find out which kind of nuts are a better buy when comparing the price per pound, and the quantities are fractional (3/4 and 1/2 lb). This lesson is meant for 7th grade or pre-algebra students.
One way is to calculate the unit price or unit rate: price for 1 pound.
The other way, in our case, is to calculate the price for 1/4 pound. It works well in this case since the quantities are 3/4 pound and 1/2 pound.
In the first part of this lesson, I solve examples that involve several operations with positive and negative fractions (and decimals), including some complex fractions.
See also
Dividing fractions & decimals, including negative ones — video lesson
Math Mammoth Rational Numbers — a self-teaching worktext where you can find worksheets to match this lesson.
Math Mammoth Grade 7 curriculum (pre-algebra)