The simple calculation of grade five includes rounding method, intersection method, bracket removal method, algorithm and subtraction property. Note that for the same calculation problem, the result of simple method is the same as that without simple method. We can check whether our calculation is correct by comparing the results obtained by the two calculation methods.

Simple operation and classification exercises in primary school mathematics

Generally speaking, the calculation order of the four operations is: when there are brackets, calculate the ones in brackets first; When there are no brackets, the second-level operation is calculated first, and then the-level operation is calculated. Only when the same level of operation, from left to right calculation.

First, there are generally five methods for simple operation:

1. rounding method: add and subtract a number to make it an integer ten, an integer hundred and an integer thousand.

2. Intersection method: also known as the law of association, several numbers are added and subtracted, and the positions are exchanged to make up an integer of ten, hundreds and thousands.

3. Method of removing brackets: Sometimes when calculating formulas with brackets, you can simplify the operation by removing brackets, but pay attention to the sign change after removing brackets.

4. Apply the algorithm.

Additive commutative law: A+B = B+A;

Additive associative law: a+b+c = a+(b+c);

Multiplicative commutative law: aXb = bXa；;

Multiplicative association law: axbxc = ax (bxc);

Multiplication and distribution law: (a+b) Xc=aXc+bXc.

5. Subtraction property: A-B A-B-C = A-C-B = A-(b+ C)； A-(B+C);

Nature of division: a+b ten c=a+c ten b=a+ (bXc).

The operation is simple, but pay attention to the sign change after removing brackets.