The Part Adder
Students work out how to break up numbers so they can calculate addition mentally. Students use a linear model and part-whole relationships to find their answer.
Teacher notes
- A partitioning model is shown so students can see the effect of breaking up numbers to solve a problem using known facts.
- The animation at the commencement of the learning object demonstrates some of the strategies, which are also available as 'hints' while students work.
- Strategies include: 'tens and ones' (where students add the 'tens' and the 'ones'); 'doubling' (where students focus on their knowledge of the two times multiplication table); 'make a ten' (where students break up one or both numbers so they are adding to a multiple of ten) and 'compensate' (where students can make one number larger and subtract the number they have added on).
- The printouts show how the student solved each equation.
Learning objects
The part-adder: generate easy sums | |
The part-adder: make your own easy sums | |
The part-adder: generate hard sums | |
The part-adder: make your own hard sums | |
The part-adder: go figure | |
The part-adder |