1, check calculation of addition and subtraction: For addition and subtraction, we can check the calculation by inverse operation. For example, for the addition problem, we can add the two addend exchange positions again to see if the results are the same; For the subtraction problem, we can subtract the exchange position of subtree and minuend again to see if the results are the same. In addition, it can also be tested by the commutative law and associative law of addition.
For example, for the addition topic: 23+45 = 68, we can check the following:
The position of the exchange addend: 45+23 = 68, the result is the same, so the answer is correct.
2. Verification calculation of multiplication and division method: For multiplication and division method, we can also use inverse operation for verification calculation. For example, for the multiplication problem, we can multiply the exchange positions of two factors to see if the results are the same; For the division problem, we can divide it by divisor and dividend at the exchange position to see if the result is the same. In addition, it can also be tested by the commutative law and associative law of multiplication.
For example, the multiplication question: 12 × 34 = 408, we can check:
The position of exchange factor: 34 × 12 = 408, the result is the same, so the answer is correct.
Benefits of practicing checking questions:
1, improve the accuracy of calculation: by practicing the examination of questions, we can help us check the correctness of the calculation results, find and correct the calculation errors in time, thus improving the accuracy of calculation.
2. Cultivate careful and serious habits: checking calculation requires us to carefully check and check the calculation results, which helps to cultivate our careful and serious habits and reduce mistakes caused by carelessness.
3. Enhance our logical thinking ability: We need to use methods such as inverse operation and estimation to check the calculation, which will help to enhance our logical thinking ability and improve our mathematical literacy.
4. Improve the speed of problem solving: By practicing the examination of questions, master all kinds of examination methods skillfully, thus improving the speed of problem solving and saving time.
5. Cultivate self-confidence: When we can accurately complete the examination questions, it will make us feel confident and satisfied, which will help to cultivate our self-confidence and self-esteem.