In this Grade 4 Saxon Math Intermediate 4 lesson, students learn to solve rate problems when the total is already known, using division to find either the missing rate or the missing amount of time. Building on earlier lessons where multiplication was used to find a total, students apply the equal groups model and write equations such as 3m = 24 to calculate average rates like miles per hour or unit earnings. Practice problems guide students through real-world contexts including reading pages, hiking distances, and hourly pay.
Section 1
📘 Rate Problems with a Given Total
Rate problems involving time consist of three quantities: a rate, an amount of time, and a total.
Next, you’ll use division to solve for a missing rate or amount of time when the total is given in a problem.
Section 2
Finding time in rate problems
To find the amount of time in a rate problem, you divide the total amount by the given rate. The formula is: Number of time groups = Total ÷ Number in each time group.
A factory produces 8 cars per hour. How long will it take to produce 64 cars? hours.
If you can read 40 pages per hour, how long will it take to read a 200-page book? hours.
Think of it like a quest! You have 100 gold coins to collect (the total), and you can grab 10 coins per minute (the rate). To figure out how long the quest takes, you just need to divide the total treasure by your grabbing speed. It’s a simple division problem to find your total time to victory!
Section 3
Finding rate in rate problems
To find the rate, you divide the total amount by the time it took to complete the task. The formula is: Number in each time group = Total ÷ Number of time groups.
A family drove 300 miles in 6 hours. Their average rate of speed was miles per hour.
If a worker earned 96 dollars for 8 hours of work, their pay rate was dollars per hour.
Ever wonder how fast you were going? If you know the total distance you traveled and how long it took, just divide the distance by the time. This gives you your average speed, or rate! It's how we calculate miles per hour or words per minute. This method is perfect for calculating your average speed on a trip!
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Section 1
📘 Rate Problems with a Given Total
Rate problems involving time consist of three quantities: a rate, an amount of time, and a total.
Next, you’ll use division to solve for a missing rate or amount of time when the total is given in a problem.
Section 2
Finding time in rate problems
To find the amount of time in a rate problem, you divide the total amount by the given rate. The formula is: Number of time groups = Total ÷ Number in each time group.
A factory produces 8 cars per hour. How long will it take to produce 64 cars? hours.
If you can read 40 pages per hour, how long will it take to read a 200-page book? hours.
Think of it like a quest! You have 100 gold coins to collect (the total), and you can grab 10 coins per minute (the rate). To figure out how long the quest takes, you just need to divide the total treasure by your grabbing speed. It’s a simple division problem to find your total time to victory!
Section 3
Finding rate in rate problems
To find the rate, you divide the total amount by the time it took to complete the task. The formula is: Number in each time group = Total ÷ Number of time groups.
A family drove 300 miles in 6 hours. Their average rate of speed was miles per hour.
If a worker earned 96 dollars for 8 hours of work, their pay rate was dollars per hour.
Ever wonder how fast you were going? If you know the total distance you traveled and how long it took, just divide the distance by the time. This gives you your average speed, or rate! It's how we calculate miles per hour or words per minute. This method is perfect for calculating your average speed on a trip!
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter