Alternate algorithms

There is rarely only one way to solve a mathematics problem. For the assigned algorithm:

1. Create an easy problem and solve it step-by-step
2. Create a more complex problem and solve it step-by-step
3. Identify key features of the algorithm
4. Provide benefits for the algorithm

Addition & subtraction

Partial sums addition

Equal-addition subtraction

Austrian subtraction

Counting-up subtraction

Multiplication & division

Lattice multiplication

Partial products

Partial products with area model (CCSS progressions, page 15)

Big 7 division (aka. partial quotients or scaffold division)

Optional

"Standard" multiplication

Line multiplication (video: Vi Hart)

Many ways of artithmetic in USCMP