1. regularization method: according to mathematical rules, some simple calculation methods are found, such as multiplication formula, addition and subtraction inverse operation, etc.

2. Approximation method: approximate a number to a number that is easier to calculate, such as rounding, rounding, etc.

3. Decomposition method: A complex calculation problem is decomposed into several simple calculation problems, and then solved one by one.

4. Consolidation method: multiple calculation problems are consolidated into one problem, and then calculated at one time.

5. Algebraic method: simplify the formula to a simpler form and then calculate it.

6. Estimation method: Determine the range of the answer by estimating the number, and then make an accurate calculation.

7. Borrowing method: In addition and subtraction, borrowing or carrying makes the calculation easier.

8. Combination method: synthesize an array into numbers that are easier to calculate, such as splitting a four-digit number into two two-digit numbers and adding them.

9. Adjustment method: according to the needs of calculation, adjust the order or position of numbers to make the calculation simpler.

10. Simplification method: simplify the number to the simplest form for calculation, for example, change 3/4+5/6 to 9/12+10/12.