Form A+B=C, how to verify whether the result c is correct? We can verify the completion by calculating C-B. If it is equal to A, the calculation is correct. If it is not equal to A, recalculate a+b, for example: 10+5= 15, and check whether the result is correct: use15 =10. Then our checking calculation is completed.

Second, the subtraction calculation

For example, A-B=C, the verification method is to calculate whether C-B is equal to A, if so, the verification is completed, if not, A-B is recalculated. For example, 20-5= 15, the calculation method is: 15+5=20. Then the calculation is correct and the calculation is completed.

Third, the multiplication operation

For example, A×B=C, the calculation method is to calculate whether C÷bis is equal to A, if it is, the calculation is completed, if it is not, A×B is recalculated. For example, 10×2=20, and the inspection method is: 20÷2= 10.

Fourth, division calculation

Form such as B÷A=C, the verification method is whether C×A is b, and if it is equal to b, the verification calculation is completed. For example: 20÷4=5, and the inspection process is 5×4=20, then the inspection is completed.