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Percentages (age 12+)

PROCEDURAL
MathematicsRatio & Proportion|Ages 12—14|ID: mt_iEXqN48w3x

Solve problems involving percentage increase, percentage decrease, finding the original value after a percentage change, and calculating simple interest

Mastery Evidence

  • Calculate a 15% increase on £240 using a decimal multiplier (× 1.15)
  • Find the original price before a 20% discount resulted in a sale price of £64
  • Calculate simple interest on £500 at 3% per annum for 4 years

Assessment Prompt

“If a bike originally costs £250 and its price goes up by 8%, can [child] work out the new price — and if a savings account earns 3% simple interest per year, how much interest would £500 earn in 4 years?”

Curriculum Standards2 alignments

7.RP.3Common Core State Standards for Mathematics
Use proportional relationships to solve multistep ratio and percent problems

Use proportional relationships to solve multistep ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error.

RP
KS3.Maths.Ratio.8The national curriculum in England
Percentage Change Problems

solve problems involving percentage change, including: percentage increase, decrease and original value problems and simple interest in financial mathematics

Mathematics · Key Stage 3

Prerequisites3

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