Rate of change
Key notes:
Rate of change = change in value / change in time
Learn with an example
✒️ A dog show enthusiast recorded the weight of the winning dog at recent dog shows.
According to the graph, what was the rate of change between 2021 and 2022?
_______ kilograms per year
Plug the numbers into the formula for rate of change and simplify.
Rate of change = change in value / change in time
= 30 kilograms – 18 kilograms / 2022 – 2021
= 30 kilograms – 18 kilograms / 1 year
= 12 kilograms / 1 year
= 12 kilograms per year
The rate of change between 2021 and 2022 was 12 kilograms per year.
✒️ A restaurant’s average food preparation time was tracked from day to day as part of an efficiency improvement programme.
According to the table, what was the rate of change between Thursday and Friday?
_____ minutes per day
Plug the numbers into the formula for rate of change and simplify.
Rate of change = change in value / change in time
= 34 minutes – 28 minutes / 1 day
= 6 minutes / 1 day
= 6 minutes per day
The rate of change between Thursday and Friday was 6minutes per day.
✒️ A restaurant’s average food preparation time was tracked from day to day as part of an efficiency improvement programme.
According to the graph, what was the rate of change between Monday and Tuesday?
_____ minutes per day
Plug the numbers into the formula for rate of change and simplify.
Rate of change = change in value / change in time
= 34 minutes – 38 minutes / 1 day
= -4 minutes
= -4 minutes per day
The rate of change between Monday and Tuesday was
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