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### Course: 6th grade (Illustrative Mathematics)>Unit 2

Lesson 7: Lesson 8: How much for one?

# Solving unit price problem

Nierria earns \$75 for tutoring 4 hours. To find her hourly rate, we divide her total earnings by the number of hours worked. By calculating 75 divided by 4, we discover that Nierria makes \$18.75 per hour for her tutoring services. Created by Sal Khan and Monterey Institute for Technology and Education.

## Want to join the conversation?

• how can i express 1 mile in 4 min???
(10 votes)
• 0.25 miles per minute
(144 votes)
• Is there any video that explains and defines what Rates are? If not, can someone help me and define it?
(2 votes)
• A rate is like a ratio.
(18 votes)
• I am still confused on ratios and units? what should i do?
(6 votes)
• HI! this lesson might get confused but here is a brief explanation.
A unit rate is a ratio between two different units with a denominator of one. When we divide a fraction's numerator by its denominator, the result is a value in decimal form. For example: 8/4 = 2 and 3/6 = 0.5. When we write numbers in decimal form, we can write them as a ratio with one as the denominator.

For example, we can write 2 as 2/1, and 0.5 as 0.5/1. However, since that approach can be a little clumsy, we usually drop the one. That said, it's important to remember the one is there, especially when working with unit rates.

For instance, 8 miles/4 hours = 2 miles/hour. Notice again that, while we did not include the 1, we did include the unit 'hour' Miles per hour is a familiar expression, as are unit rates such as:

interest/amount invested
revolutions/minute
salary/year
Hope this helps!
(25 votes)
• Jacqueline spends 20% of her money on sweets and 32% on fares. if she spent \$8 on sweets what is. (1) the amount of money she has left (2) The amount of money spent on fares (3) The amount she has left. I need help with this problem I am working on finding percentages using the unitary method on a calculator. But no matter what I do, I can't figure out the answers to this problem. what am I doing wrong?
(8 votes)
• Set up a proportion using the information for sweets: 8/n = 20/100
Cross multiply: 20n = 800
Divide by 20: n = \$40
This means Jacqueline started with \$40

You can find the amount spent on fares by doing: x/40 = 32/100
Cross multiply: 100x = 1280
Divide by 100: x = \$12.80
So, she spent \$12.80 on fares

To find amount left, do: 40 - 8 - 12.80

Hope this helps.
(10 votes)
• who else used a calculator for this?
(10 votes)
• me. lol
(3 votes)
• Thank you for the help! You are so kind.
(7 votes)
• Reduce the following rates to their unit rate forms. Write the numerator of each unit rate in the box provided.
\$40 per 8 Hours
(4 votes)
• You need to find dollars per hour.
Divide: 40/8 to find you answer.
(8 votes)
• let this be the most upvoted comment ever
(7 votes)
• At , the company should charge for area not number of offices because it could be huge and another one is small and both are then same price.
(7 votes)
• Yes, but it is a fictional company for one's education, not a real situation.
(0 votes)
• What is an easyer way to divide
(1 vote)

## Video transcript

- [Instructor] We're told that Nierria earns \$75 for 4 hours of tutoring. How much does Nierria earn for 1 hour of tutoring? Pause this video, and see if you can figure that out. Well, the key here is \$75 for 4 hours of tutoring. And there's a couple of ways you can think about it. The ratio here is \$75 for every 4 hours. So if you wanted one hour of tutoring, well, it's just going to be 1/4 of the \$75, or you could just take 75 and divide by 4. Another way you could think about it, you could say Nierria gets \$75 for every 4 hours, which is another way of saying that Nierria is going to earn 75 divided by 4 dollars per hour. So really we just have to figure out what 75 divided by 4 is. So let's do a little bit of long division. So 4 goes into 7 one time, 1 times 4 is 4. We're going to subtract. 7 minus 4 is 3. Bring down that 5. 4 goes into 35 eight times. 8 times 4 is 32. I will subtract again. I get a 3. Well now I'm going to get some decimals here, so let me bring down a zero. 4 goes into 30 seven times. 7 times 4 is 28. Subtract, and then I get a 2. Bring down another zero. 4 goes into 20 five times. 5 times 4 is 20, and I am done, no more remainder here. So we get that Nierria earns 18.75 dollars, dollars per hour, or you can just say that she makes \$18.75 per hour.