Number Framework Stage 4 and 5.
Materials suitable for bundling into tens (e.g., sticks with rubber bands around bundles of ten, or beans in lots of ten in film canisters or plastic bags).
Using materials
Problem: There are ten stickers in each packet. Miranda has three packets and her grandfather buys her two more packets. How many stickers does Miranda have altogether?
Model 30 on the abacus by showing three rows of ten (or model on the bundled sticks or container materials).
Ask the students how to model twenty.
Discuss what has been modelled; for example, three packets (of ten) plus two packets (of ten).
Record “3 packets (of 10) + 2 packets (of 10)” on the board or in the modelling book.
Below this, record 30 + 20.
Discuss what basic fact will help to find the answer.
Record the solution to 30 + 20 on the board or in the modelling book.
Examples: Word problems and recording for: 3 packets + 1 packet, 5 packets – 1 packet, 1 packet + 5 packets, 60 – 20, 80 + 10 …
Using imaging
Problem: A packet contains ten lollies. If Matiu has seven packets and Andrew has one packet, how many lollies do Matiu and Andrew have altogether?
Record “7 packets of 10 + 1 packet of 10”, and below this, 70 + 10, on the board or in the modelling book.
Out of sight of the students, model 70 on the abacus. Ask them what the model looks like.
Model 10 more. Ask the students what the model looks like now.
Record the solution to 70 + 10 on the board or in the modelling book.
Examples: 5 packets + 3 packets, 5 packets – 1 packet, 4 packets + 2 packets, 10 + 50, 90 – 40, 30 + 20, 50 – 40, 50 + 10, 80 + 10 …