1, addition calculation:
We can exchange the positions of addends for recalculation, or we can use subtraction for reverse calculation. For example, 25+36=6 1, we can get 36+25=6 1 by exchanging the positions of addends, or we can check whether the original calculation is correct by 6 1-25=36.
2, subtraction calculation:
We can calculate it by adding the difference to the reciprocal of subtraction, or by adding it in reverse. For example, 72-8=64, we can check whether the original calculation is correct by the reciprocal of 8 (-8)+64=72 or 72+(-8)=64.
3. Multiplication calculation:
We can exchange the position of the multiplier and recalculate it, or reverse it by division. For example, 3×4= 12, we can verify that the original calculation is correct by 4×3= 12 ÷ 3 = 4 or 12÷4=3.
4, division calculation:
We can divide the dividend by the quotient, or multiply it in reverse. For example, if 15÷3=5, we can check whether the original calculation is correct by 5×3= 15 or 15÷5=3.
The important role of mathematical checking calculation;
1, check the accuracy of the calculation results:
Mathematical check can help us check whether there are errors or omissions in the calculation process, thus ensuring the accuracy of the calculation results. In mathematical calculation, various reasons (such as carelessness, fatigue, inaccurate understanding, etc. ) may lead to calculation errors, which can be effectively avoided by checking calculation.
2, deepen the understanding of arithmetic:
Mathematical examination requires students to have a deep understanding of the rules, properties and theorems of arithmetic operations. Through the examination, students can have a deeper understanding of arithmetic, so as to better master mathematical knowledge. For example, the commutative law and associative law of addition and the distributive law of multiplication can be deepened in the inspection process.
3. Improve self-confidence in solving problems;
By checking, we can be sure that our answer is correct. In exams or homework, if you have doubts about the accuracy of the calculation results, you can check them to improve your self-confidence and reduce your worries about the results. Correct grades can also enhance students' self-confidence in learning.