Addition of negative numbers

3 Arithmetic
3.17 Addition of negative numbers
Now think about adding a negative number, by looking at the number line again. Suppose you start at 0. Since 0 + −3 is the same as −3, you would expect that adding −3 to 0 on the number line should take you to the point marked −3 on the number line. So, 0 + −3 = −3.

Suppose Thomas's piggy bank were empty and he added an IOU for £3 to it. The value of the piggy bank would be −3.




To reach −3 from 0, move 3 units to the left. In general to add a negative number you move to the left along the number line.#



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