Fraction addition and subtraction mixed operation method: 1, same denominator fraction addition and subtraction: the denominator of the fraction remains unchanged, and the numerator is added and subtracted. 2. Addition and subtraction of fractions with different denominators: first divide the fractions and convert them into fractions with the same denominator for calculation. 3. Fractional addition and subtraction mixed operation method: the same as integer addition and subtraction mixed operation order. 4. Simple arithmetic: The arithmetic of integer addition is also applicable to fractions. Decimal reduction is a common mistake: 1. The basic nature of misusing scores. When dividing, the numerator and denominator do not divide at the same time. Don't take it for granted Many times it is so careless and wrong. 2. The simplest score can't be transformed, some people are incomplete, some people can't find the common factor for a long time, and some people can't even find the greatest common factor. 3. I don't understand the requirements of the topic. For example, I asked to express the quotient of a division formula with a fraction or the simplest fraction, and I didn't understand what the final quotient was, so I was at a loss.