how do I explain addition and subtraction of negative numbers?
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Anonymous
| More specifically, how do I explain to DC that subtracting a negative number is like adding a positive number? It seems so intuitive that I can't come up with a cogent explanation. |
Anonymous
| Use a number line |
Anonymous
| Number line. Make it visual. |
Anonymous
| Don't know how old your kids are, but I used a thermometer to show my kids this concept. It was especially useful when they borrowed against their allowance. |
Anonymous
| What about thinking about it with the example of money? In that case, negative numbers mean you owe money. If someone takes away some of the debt, you have more money (or at least owe less). |
Anonymous
| Use a number line with zero in the middle, with positive numbers to the right and negative numbers to the left. This way you can plot the problem on the number line. You can use buttons, pennies, or any other small manipulatives to demonstrate. |
Anonymous
|
Use money as an example. Negative numbers are debt in this scenario. So explain that if you have $2, that is a +2. If you have a debt of $2, that is -2. So what happens when you take away a debt of $2? So you are effectively subtracting -2. So if you are planning on repaying a $2 debt to your friend but then they say never mind and cancel the debt, you are effectively $2 richer (+2)
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Anonymous
| Thank you all! |