At elementary school learn how to put and subtract numbers. To learn to do it, it is necessary to learn the table of addition and the table of subtraction based on it. It turns out, the first grader will be able to subtract from seventeen nine or to solve any similar example. However the example of the return character will be able to lead into a blind alley him: how to subtract from nine seventeen. Examples with negative numbers are given according to the school program much later when the person ripens to abstract thinking.
Instruction
1. Mathematical operations there are four views: addition, subtraction, multiplication and division. Therefore examples with minuses there will be four types. Negative numbers in an example are allocated with brackets not to mix mathematical operation. For example, 6-(-7), 5+(-9),-4*(-3) or 34:(-17).
2. Addition. This action can have an appearance: 1) 3+(-6) =3-6=-3. Action replacement: at first the brackets, the sign ""+" are removed changes on opposite, further from bigger (on the module) numbers ""6"" smaller - ""3"" then the sign bigger is appropriated to the answer, that is "" -"".2)-3+6=3 is taken away. This example can be written down in a different way (""6-3"") or to solve by the principle ""from bigger to take away smaller and to appropriate to the answer the sign bigger"".3)-3+(-6)=-3-6=-9. At removal of brackets there is a replacement of action of addition by subtraction, then modules of numbers are summarized and to result to be put the sign ""minus"".
3. Subtraction.1) 8-(-5)=8+5=13. The brackets are removed, the sign of action changes on opposite, the example on addition.2)-9-3=-12 turns out. Elements of an example develop and the answer receives the general sign "" -"".3)-10-(-5)=-10+5=-5. At removal of brackets the sign on ""+" changes again, further from bigger number it is taken away smaller and from the answer - the sign of bigger number.
4. Multiplication and division. When performing multiplication or division the sign does not influence action. At the work or division of numbers with different signs the sign ""minus"" is appropriated to the answer if numbers with identical signs - at result always sign ""plus"".1)-4*9=-36;-6:2=-3.2) 6*(-5)=-30; 45:(-5))-7*(-8)=56;-44: (-11) =4.