1. NOT have to be a whole number.
Writing and Solving Proportions
Proportion:
You can often use a ______________________________ (or equivalent ratio) to solve for an unknown number in a proportion.
Notes: A one in disguise does ________________________________________
If you can’t find a one in disguise, try ____________________
An equation showing two fractions (or ratios) are equal.
One in Disguise
NOT have to be a whole number.
Cross-Products!

2. to match up labels appropriately.
Steps to setting up a proportion from a word problem:
1) Be careful
For example, you cannot write a proportion to compare
2) Solve
3) Make
Set up a proportion to solve. Then solve.
7. At a store, 5 erasers cost $ Yesterday you rode your bike 18 miles in 2.5 hours.
How many erasers can you buy for $7.50? Today you plan to ride for 3.5 hours. If you ride
at the same rate as yesterday, how far will you ride?
to match up labels appropriately.
There are SEVERAL CORRECT ways to set one up.
the proportion using a one in disguise or cross-products.
sure your answer makes sense in the context of the problem.