A sample starts at 500 grams and loses 18% each hour. How much remains after 5 hours?
Reasoning Strategy
Use a decay factor of 0.82 for each hour.
AI Support Preview
Translate losing 18% into keeping 82%.
Public Practice Guide
Use this guide to see the type of reasoning MathRoutine expects for grade 9 exponential growth and decay word problems. The goal is not worksheet volume; it is helping students read the situation, choose a model, and explain why the answer fits.
What Students Practice
Reasoning Patterns
Sample Problems
These grade-specific examples show the kind of student-visible reasoning MathRoutine is designed to support: identifying the important quantities, choosing the right structure, and checking the final answer against the story.
A sample starts at 500 grams and loses 18% each hour. How much remains after 5 hours?
Reasoning Strategy
Use a decay factor of 0.82 for each hour.
AI Support Preview
Translate losing 18% into keeping 82%.
Practice Ladder
Modeled after Algebra 1/Algebra 2 workbook expectations: interpret a function or equation in context, solve or compare it, then justify the meaning of the answer.
Connect the equation form to the real situation before calculating.
Evaluate, reverse, or compare the model while tracking restrictions and units.
Use the result to answer the actual question, not just the algebraic expression.
Assessment Signals
A guide is useful only if it clarifies what teachers and parents should look for in student work. MathRoutine tracks these signals during practice instead of treating every miss as the same mistake.
Common Mistakes
Learning Loop
A strong word problem platform should not only say right or wrong. It should notice the pattern: missed unit rate, ignored leftover, reversed comparison, wrong base percent, or equation setup error.
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Attempt
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Diagnosis
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Next practice
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