Wei's quick calculation 1, quick addition calculation: the quick addition calculation method of any number of digits is very simple. As long as learners remember a general formula for fast addition calculation-"standard addition (for decimal digits) minus plus complement, and the previous digit plus one", they can completely solve the fast addition method of any digit from high to low. For example: (1) 67+48 = (6+5 )×10+(7-2) =15 (2) 758+496 = (7+5 )×100.
2. Fast subtraction: The fast subtraction method for calculating any digit is also a general formula for fast subtraction-"Standard subtraction (borrowed digits) plus or minus the previous digit" can completely solve the fast subtraction method for counting any digit from high to low, such as: (1), 67-48 = (6-5) × 6544.
3. Fast multiplication: The general formula of Wei's fast multiplication is AB× CD = (a+1)× C×100+B× D+the number of Wei's fast multiplication×10.
Evaluation method of mathematical fast calculation skills
Estimation method is a fast method for rough estimation under the condition of low accuracy requirement.
Usually used when the options are very different, or when the compared data are very different. There are many ways of assessment, which require each candidate to have more training and mastery in actual combat.
Only when there is a big difference between the options or the numbers to be compared will the evaluation be made, and the size of the difference determines the accuracy required for the "evaluation".
Homology method
The so-called "assimilation method" refers to a quick method that "when comparing two fractions, the numerator or denominator of the two fractions will be the same or similar for a long time, thus simplifying the calculation".
1. or the denominator becomes exactly the same, depending on the denominator or the numerator.
2. When the numerator or denominator is similar, it can be directly judged that the denominator of a fraction is small or the denominator of a fraction is large.
amitosis
"Direct division" is a method to get the first place of quotient quickly and get the correct answer when comparing or calculating complex numbers. "Direct division" generally includes two types of problems:
1. When comparing multiple fractions, the first maximum/minimum number is the maximum/decimal with equal order of magnitude.
2. When calculating the score, you can choose the correct answer by calculating the first position of different options.
"Direct score" is generally divided into three gradients according to difficulty:
1. You can directly see the first transaction.
You can see the first business by doing the calculation.
3. For some complicated scores, you need to calculate the first reciprocal of the score to determine the answer.