Alternate Addition and Subtraction Algorithms

Optional: Review the student invented algorithms from Friday's class and homework:

Addition Subtraction
Adding on in chunks using multiples of 10 and 100 as bridge numbers Adding up to the minuend in chunks using multiples of 10 (and 100) as bridge numbers (I have also posted in the content section of D2L a video of a class discussing this strategy)
Add in place values and combine Subtract in place values using negative numbers, the negative numbers algorithm
Add highest place values and compensate Subtract highest place values and compensate

First part of the assignment:

Learn about these algorithms that teachers sometimes find it useful to teach before or along side the standard algorithms:

Addition Subtraction
Expanded addition Break into place values (expanded subtraction)

Practice and turn as homework:

Use the expanded algorithm for addition to solve 386 + 247

Use the expanded algorithm for subtraction to solve 523 - 165

Here's a text version explaining the algorithms.

Second part of the assignment.

Find a video on the internet showing a way of adding or subtracting that is different from the usual "carrying" or "borrowing" algorithm that is standard in US textbooks. Submit as a Word file to the D2L dropbox the url (web address) of the video you found, and an in-words explanation you have written of how this strategy works. I recommend a google search using the some of the search terms: "addition" "subtraction" "number talk" "strategy" "alternate"