Directed numbers
I have taken to putting a small version of the table below in the top right of my PowerPoint slides and as an A3 poster on the (ink powered) whiteboards I use in many teaching rooms.
Students at level 2 doing algebra need to use these facts in most lessons, and seeing the rules all in one place seems to help.
I feel a YouTube coming on once I shift this cold…
A pair of directed numbers…. | Adding and subtracting | Multiplying and dividing |
Same signs | Add the numbers | The answer will be positive |
Opposite signs | Find the difference of the numbers | The answer will be negative |