Reverse Percentages 18012022 WALT work backwards to calculate

Reverse Percentages 18/01/2022 WALT: work backwards to calculate original amounts in percentage problems Question A pair of shoes are reduced by 20% in a sale. The sale price is £ 48. What was the original price? Answer 20% of £ 48 = £ 9. 60 £ 48 + £ 9. 60 = £ 57. 60 So, Original price = £ 57. 60 Is this answer correct? Why not?

Question A pair of shoes are reduced by 20% in a sale. The sale price is £ 48. What was the original price? Answer 20% of £ 48 = £ 9. 60 £ 48 + £ 9. 60 = £ 57. 60 So, Original price = £ 57. 60

Reverse Percentages Original Amount 100% value EXAMPLES (a) Mavis paid £ 48 for shoes that had been reduced by 20% in a sale. What was the original price?

Reverse Percentages Original Amount 100% value EXAMPLES (b) George received an 8% pay rise. His new salary is now £ 19200. What was his original salary?

Your Turn 1) A quantity is decreased by 3%. It now has a mass of 38. 8 kg. What was the original mass? 2) A coat was advertised in a sale at £ 79 after a 5% reduction. What was the original price? 3) Bobby’s salary was increased by 7%. His new salary after the pay rise is £ 28, 890. What was his original salary? 4) In a local election Labour received 1375 votes. This was 12% up on the previous election. What was their previous number of votes? 5) A charity’s income has been reduced by 12. 5%. It’s income is now £ 49 000 per year. What revenue? was it’s previous

Your Turn 1) A quantity is decreased by 3%. It now has a mass of 38. 8 kg. What was the original mass? 40 kg 2) A coat was advertised in a sale at £ 79 after a 5% reduction. What was the original price? £ 83. 16 3) Bobby’s salary was increased by 7%. His new salary after the pay rise is £ 28, 890. What was his original salary? £ 27 000 4) In a local election Labour received 1375 votes. This was 12% up on the previous election. 1228 votes What was their previous number of votes? 5) A charity’s income has been reduced by 12. 5%. It’s income is now £ 49 000 per year. What revenue? £ 56 000 was it’s previous

Percentages Problem Solving Miss Cradick wants to go to Essex for the weekend. The cost of a standard return ticket is £ 111. 10. Will it be cheaper for me to buy my ticket with trainline or virgin trains? (Assuming I will pay by credit card) Train. Line Credit Card Charge 2% of ticket price Booking fee £ 1. 50 Credit card charge 3. 5% of ticket price No Booking fee Extension I paid a total amount of £ 86. 84 on my credit card for a ticket from Virgin. What was the cost of the ticket before the credit card charge was added?

Percentages Problem Solving 18/01/2022 £ 111. 10 Train. Line Credit Card Charge 2% of ticket price Booking fee £ 1. 50 Credit card charge 3. 5% of ticket price No Booking fee Train line is cheaper by 17 p

Percentages Problem Solving 18/01/2022 Extension I paid a total amount of £ 86. 84 on my credit card for a ticket from Virgin. Credit card charge 3. 5% of What was the cost of the ticket before ticket price the credit card charge was added? No Booking fee = £ 83. 90

Marking Guide –RAG 123 Feedback – End of – Lesson I have learned how to Do you understand the … during WALT? I was able to … What went well in today’s lesson? today’s lesson. What didn’t you understand today? I don’t understand … What helped you make progress today? What will help you make more progress? What do you need to do Cymraeg@Martin. Sa next? nt … helped me progress today. I would like to … I need to … to make further progress