Hi Khan Academy Members,
I have been working on this for quite a while now and somehow this is a big challenge for me. I have watched the videos on Khan Academy etc. but am still getting rather confused by the topic for example:
−2−(−7)=
Is there a simple way to remembering to subtract negative numbers or you have developed a system to remember any tips would be appreciated.
When dealing with adding or subtracting negative numbers, I always think of a number line.
For this question, picture the number line starting at -2.
Now, you are trying to subtract a negative number, right? Subtracting a negative number is the same thing as adding a positive. -2-(-7) is the same thing as -2+7.
Imagine it like this: if I'm taking away a debt from my back account, wouldn't that mean I'm increasing or adding to my balance?
To solve -2+7 now, just imagine starting at -2 and hopping 7 places to the right, or adding 7. You would end up at 5.
So, -2-(-7)=5
Imagining a number line is one of the best methods to solve these kinds of problems!
Please sign in to leave a comment.