This isn’t something you do everyday. Therefore it would be helpful to know how to remember it long term.
Notice the PLUS sign? That’s the big key to doing this.
This video shows the long expanded way that most people won’t show you. You wouldn’t really convert this way, but it helps to see it in the long form. This way you know what your teacher is showing you isn’t some pixie dust magic:
Now that you can do that, you can probably go the other way too:
And how about checking your work? Nevermind the devil box (aka the calculator), the more you check your own work by hand, the more your confidence in your own math abilities will be. Try doing this:
What do you think? Will this help you remember? Do you have another way to remember? Share it in the comments section.
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