Free Grade 3 Best Buy Problems Flashcards
Free Grade 3 flashcards for Best Buy Problems: 12 real questions with a full answer key and worked solutions. In direct proportion, when one amount doubles the other doubles too. Find the value of one unit, then scale up.
Free
Core
20 min
24
Learning objectives
Every objective is checkable, and each one maps to an activity and an assessment.
- RememberIdentify best buy problems
Identify best buy problems accurately in a familiar context.
Assessed by: Exit ticket of four short items
- UnderstandExplain best buy problems
Explain best buy problems accurately in a familiar context.
Assessed by: Exit ticket of four short items
- ApplyCalculate best buy problems
Calculate best buy problems accurately in a familiar context.
Assessed by: Exit ticket of four short items
- AnalyseCompare best buy problems
Compare best buy problems accurately in a familiar context.
Assessed by: Exit ticket of four short items
Prerequisites
Close these gaps first — each has its own free lesson, worksheet and quiz.
How Best Buy Problems works
In direct proportion, when one amount doubles the other doubles too. Find the value of one unit, then scale up.
12 practice questions
Easy to hard, 24 marks in total. Try them first, then open the answers.
- 1.4 pens cost $18.00. How much do 5 pens cost?[1]
- 2.2 pens cost $4.00. How much do 6 pens cost?[1]
- 3.3 pens cost $16.50. How much do 7 pens cost?[1]
- 4.3 pens cost $16.50. How much do 10 pens cost?[1]
- 5.4 pens cost $40.00. How much do 7 pens cost?[2]
- 6.4 pens cost $24.00. How much do 5 pens cost?[2]
- 7.3 pens cost $42.00. How much do 9 pens cost?[2]
- 8.6 pens cost $84.00. How much do 8 pens cost?[2]
- 9.2 pens cost $39.00. How much do 7 pens cost?[3]
- 10.3 pens cost $63.00. How much do 11 pens cost?[3]
- 11.3 pens cost $63.00. How much do 9 pens cost?[3]
- 12.6 pens cost $117.00. How much do 6 pens cost?[3]
Show answers and working
1. $22.50
Cost of 1 pen: $18.00 ÷ 4 = $4.50. 5 pens: 5 × $4.50 = $22.50.
2. $12.00
Cost of 1 pen: $4.00 ÷ 2 = $2.00. 6 pens: 6 × $2.00 = $12.00.
3. $38.50
Cost of 1 pen: $16.50 ÷ 3 = $5.50. 7 pens: 7 × $5.50 = $38.50.
4. $55.00
Cost of 1 pen: $16.50 ÷ 3 = $5.50. 10 pens: 10 × $5.50 = $55.00.
5. $70.00
Cost of 1 pen: $40.00 ÷ 4 = $10.00. 7 pens: 7 × $10.00 = $70.00.
6. $30.00
Cost of 1 pen: $24.00 ÷ 4 = $6.00. 5 pens: 5 × $6.00 = $30.00.
7. $126.00
Cost of 1 pen: $42.00 ÷ 3 = $14.00. 9 pens: 9 × $14.00 = $126.00.
8. $112.00
Cost of 1 pen: $84.00 ÷ 6 = $14.00. 8 pens: 8 × $14.00 = $112.00.
9. $136.50
Cost of 1 pen: $39.00 ÷ 2 = $19.50. 7 pens: 7 × $19.50 = $136.50.
10. $231.00
Cost of 1 pen: $63.00 ÷ 3 = $21.00. 11 pens: 11 × $21.00 = $231.00.
11. $189.00
Cost of 1 pen: $63.00 ÷ 3 = $21.00. 9 pens: 9 × $21.00 = $189.00.
12. $117.00
Cost of 1 pen: $117.00 ÷ 6 = $19.50. 6 pens: 6 × $19.50 = $117.00.
Worked examples
6 pens cost $39.00. How much do 11 pens cost?
- Cost of 1 pen: $39.00 ÷ 6 = $6.50.
- 11 pens: 11 × $6.50 = $71.50.
- Answer: $71.50
5 pens cost $20.00. How much do 5 pens cost?
- Cost of 1 pen: $20.00 ÷ 5 = $4.00.
- 5 pens: 5 × $4.00 = $20.00.
- Answer: $20.00
5 pens cost $97.50. How much do 8 pens cost?
- Cost of 1 pen: $97.50 ÷ 5 = $19.50.
- 8 pens: 8 × $19.50 = $156.00.
- Answer: $156.00
Interactive practice
Free, no account required — answer on screen or print it.
Common mistakes
What learners typically get wrong, and how to fix it.
Adds instead of scaling.
Correction: Work out the cost of ONE first.
Rounds the unit price too early.
Correction: Keep the exact unit value until the end.
Teacher tips
- · Use a ratio table to keep working organised.
Parent tips
- · Compare price per item on multipacks.
Real-life applications
- · Best-value shopping, currency conversion.
Assessment objectives
How mastery is evidenced, and which standards it maps to.
Every free resource for Best Buy Problems
One concept, one ecosystem — all of it free.
Goes deeper
The entities below this one, each with the same complete free resource set.
Sibling concepts
Related concepts
Lateral links, including across subjects.
Next topics
All free formats for this concept
Every kind below is a real page, generated from this entity.
Learn — Meet the idea.
Practice — Build fluency.
Revise — Keep it in memory.
Assess — Prove mastery.
Apply — Use it in context.
Teach — Deliver it to a class.
Frequently asked
- Is this Grade 3 Best Buy Problems flashcards really free?
- Yes. Every flashcards on FreeMathWorksheet is free to use, print and share — no account, no paywall and no watermark.
- What should a learner already know before this?
- Start with Scale Factors, Inverse Proportion, Ratio. Each one has its own free lesson, worksheet and quiz.
- How is the flashcards sequenced?
- Recognition first, then understanding, application, reasoning and finally mastery — the same ladder used across every free resource on the platform.
- What comes next after Best Buy Problems?
- Move on to Whole Numbers, Counting, Number Recognition, Number Formation, which build directly on this idea.
Related resources
Stuck on Best Buy Problems? The AI Tutor already knows this page, its prerequisites and its common mistakes.
Open the free AI Tutor