The steps and examples of the simple calculation method of (1) five-stage separation are briefly described as follows:
1. When two numbers A and B are multiplied or divided by the same number C at the same time, and then add and subtract, you can add and subtract the two numbers A and B first, and then multiply and divide with C, as follows:
0.5÷2-0. 15÷2=(0.5-0. 15)÷2=0.35÷2=0. 175;
0.5x 2-0. 15x 2 =(0.5-0. 15)X2 = 0.35 x2 = 0.7;
2. When the conditions of addition, subtraction, multiplication and division are not as good as above, that is, when the four natural numbers of abcd are irregular, you must first add, subtract, multiply and divide (calculate a÷b and c×d first), and then add and subtract, as follows:
2.88 1÷0.43-0.24×3.5 = 6.7-0.24 x 3.5 = 6.7-0.84 = 5.86;
3. Between large, medium and small brackets and multiplication, division, addition and subtraction, first calculate the number in brackets, then calculate the number in brackets, and finally multiply, divide, add and subtract the number outside brackets, as follows:
30.8÷[ 14-(9.85+ 1.07)]=30.8÷( 14- 10.92)=30.8÷3.08= 10;
(2) Summary of simple off calculation skills:
1, offline calculation is recursive equation calculation, and the operation of completely writing out the calculation process is also offline calculation. When calculating mixed operations, it is usually to calculate an expression step by step and step by step. The equal sign cannot be written on the original formula, but the process of each step should be written.
2. The equal sign should be forward and not aligned with the first line. That is, to leave the original calculation. The main thing to master is to remember to calculate multiplication and division first, and then add and subtract. In the continuous calculation of multiplication and division, it should be calculated from left to right.
3. When you encounter brackets, you must first calculate the inside of the brackets. In the process of separation, the operation sequence line should be drawn according to the operation sequence, and the "three checks" should be done well. First of all, check whether the numbers and symbols copied from books to exercise books are correct. Second, check whether the numbers and symbols copied from horizontal to vertical are copied correctly. Third, it is necessary to check whether the draft is copied vertically, horizontally, and whether the decimal point position is correct or not.
The above is the whole content of simple off-line calculation. The answer is not easy, hope to adopt. Thank you very much for your kindness.