What is a ratio

what are like numbers

the relative magnitudes of two like numbers

In story problems, like numbers are numbers with the same units

Define the relationship between two amounts

when can it be used

simple related terms have numerical values units

can be used to construct conversion factors and proportions

What are direct proportions

what can be directly proportional

as one value doubles, an associated value double

ratios or related terms

what are inverse proportions? 2

what is one example of this? explain

less common than direct proportions

as one value goes up, the related value goes down

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Dilutions:  when we dilute something, the volume goes up but the concentration goes down

what is important to know when using inverse proportions

2

always use ratios

put the related  terms in opposite positions

what is important to know when using proportions to solve complex calculations

2

requires multiple steps

allows us to see our intermediate answers and more easily identify our mistakes

What is dimensional analysis

2

solution can be deduced by the units that the answer should have

use a string of related terms that are placed such that their units cancel to those that you have determined for the answer

benefits of dimensional analysis

3

efficient

hard to identify your mistakes

if you have a substance that doesn't look right, make sure you label you rnumbers with both units and substance