CCSS.Math.Content.HSF-LE.A.1c
The Standard
Recognize situations in which a quantity grows or decays by a constant percent rate per unit interval relative to another.
Common Core State Standards for Mathematics · Construct and compare linear, quadratic, and exponential models and solve problems
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students identify situations where a quantity changes by the same percent during each equal interval. They distinguish this pattern from adding or subtracting the same amount.
What Mastery Looks Like
- Given a table, graph, formula, or situation, students can identify percent growth or decay and state the rate. They support their choice using equal ratios or equal percent changes across intervals.
Common Misconceptions
- Students often confuse a constant percent change with a constant numerical change. They may compare differences instead of ratios or calculate each change from the starting value rather than the previous value.
How to Assess It
- Exit ticket: A phone worth $800 loses 15% of its value each year. Explain what stays constant, then find its value after two years.
Lesson moves
Ways to Teach It
Give groups 100 counters, then have them add 20% of the current pile each round and record each total.
Ask students to compare adding $50 yearly with increasing by 5% yearly, then explain which pattern has a constant ratio.
Run a card sort with tables, formulas, and scenarios labeled constant percent change, constant numerical change, or neither.
Use a used car price chart to calculate yearly percent depreciation and decide whether an exponential model is reasonable.
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Printable HSF-LE.A.1c Worksheet
A ready-to-print activity worksheet aligned to CCSS.Math.Content.HSF-LE.A.1c, with an answer key for the teacher on its own page. No account needed.
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Where This Standard Sits
Before This Standard
If students are struggling here, check these first.
- CCSS.Math.Content.HSF-LE.A.1a
Recognizing constant percent change uses the idea that exponential growth multiplies by the same factor each interval.
- CCSS.Math.Content.7.RP.A.3
Solving percent problems supports interpreting a constant percent change per interval, though exponential change is not itself proportional.
- CCSS.Math.Content.HSF-BF.A.2
Geometric sequences give the repeated multiplication idea needed to recognize constant percent growth or decay across equal intervals.
Keep exploring
Related Standards
- CCSS.Math.Content.7.RP.A.2
Recognize and represent proportional relationships between quantities.
- CCSS.Math.Content.HSF-IF.B.6
Calculate and interpret the average rate of change of a function (presented symbolically or as a table) over a specified interval. Estimate the rate of change f...
- CCSS.Math.Content.7.RP.A.2b
Identify the constant of proportionality (unit rate) in tables, graphs, equations, diagrams, and verbal descriptions of proportional relationships.
- CCSS.Math.Content.HSF-LE.A.1b
Recognize situations in which one quantity changes at a constant rate per unit interval relative to another.
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