Teaching and Group Activities for Understanding
Day 1 Teaching
Display a pen priced 45p. Say you will buy this and pay with 50p. Use a 0–50 line to show how we can count up from 45p to 50p to find change. Show how we can cross out 0–45 and see what is left. Repeat with a sharpener costing 48p. Show that if you spent 2p, you would get 48p change. Repeat for 43p.
-- Find change from 50p when buying items that cost forty-something pence.
-- Find change from 10p.
Day 2 Teaching
Show a problem. Matthew had £17 and spent £15 on an art set. How much money has he left? Mark 17 on a 0–20 beaded line. Emphasise that Matthew spent £15, so cross out 0–15. Explain that he has 2 left. Show lines of 15 and 17 on ITP Difference to reinforce. Repeat with a spend of £14.
Use the in-depth problem-solving investigation ‘Combining Coins’ from NRICH as today’s group activity.
Or, use this activity:
-- Find the difference between two 2-digit numbers by counting up.
-- Decide whether to count up or back to find change in pounds.