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## Algebra 1

### Course: Algebra 1 > Unit 3

Lesson 3: Word problems with multiple units# Working with units: FAQ

Frequently asked questions about working with units

## Why is it important to be able to convert rates?

Often, we want to compare two rates that are expressed in different units. We need to convert one of the rates to match the other one in order to make a meaningful comparison.

Practice with our Rate conversion
exercise.

## How do we go about choosing appropriate quantities for modeling?

It depends on the problem we're trying to solve. We'll want to choose quantities that are relevant to the problem and that we're able to measure directly or indirectly. For example, if we're trying to model the speed of a car, we might want to use distance and time as our quantities.

Practice with our Defining appropriate quantities for modeling
exercise.

## How can we use formulas and units to solve problems?

By using formulas that relate different quantities to each other, we can use known values to solve for unknown values. Units are important because they remind us what the quantities represent and help us to check our work.

Practice with our Formulas and units
exercise.

## What are some real-world applications of these topics?

There are countless examples! Engineers use rate conversions in order to design systems that operate at different speeds or frequencies. Scientists use formulas and units to solve problems ranging from calculating the densities of substances to measuring the rates of chemical reactions. And of course, people in all sorts of professions use these skills to make everyday calculations, such as converting measurements for a recipe or determining how long it will take to drive somewhere based on the speed limit.

Practice with our Using units to solve problems
exercise.

## Want to join the conversation?

- I hate this unit no matter how I try it just won't work uggghhhh! ?(16 votes)
- stay persistent homie thats what i used to feel(17 votes)

- This stuff hard(10 votes)
- you'll figure it out(3 votes)

- Y'all! Am I the only one who is still having trouble with this? It's making my brain hurt.(8 votes)
- You're definitely not the only one lol(3 votes)

- Math aint for me no more(7 votes)
- same, goofy ah mid math(4 votes)

- Express 160 pounds (lbs) in kilograms (kg). Round your final answer 2 decimal places.

Units of Length Units of Weight Units of Capacity

1 in. = 2.54 cm 1 oz ≈ 28.35 g 1 L ≈ 1.06 qt

1 m ≈ 3.28 ft 1lb ≈454 g 1 gal ≈ 3.79 L

1 m ≈ 1.09 yd 1 kg ≈ 2.2 lb

1 mi ≈ 1. 61 km(7 votes) - What happens if the quantity for modeling is not appropiate?(4 votes)
- Yes, this is very important for many different careers.

•you need to know drug conversion if your going to be a doctor or paramedic.

•if you want to be a chemist you'll need to be able to convert between different chemical measurements.

• if your trading currency you have to be able to convert between currencies.

While most of these can be done via computer, it can still be a very useful skill to have. Hope this helps!(11 votes)

- How this can work in real life(2 votes)
- It could be helpful when using a recipe for cooking or following a blueprint that uses different units to measure in(5 votes)

- When will I use this in day-to-day life, besides in the work field, I will most likely not join.(1 vote)
- You will use it everyday. Like for example, when you spend money or play games or other stuff like that.(4 votes)

- My brain is dying!(2 votes)