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 |
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) |
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.
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"