Electronic teaching materials are necessary resources for children to preview the knowledge of the new semester. The related content on page 28 is fractional division, which is the reverse operation of fractional multiplication. The calculation rule of fractional division is: A divided by B (except 0) equals the reciprocal of A multiplied by B. The result of fractional division can be reduced to providing points. When the divisor is less than 1, the quotient is greater than the dividend; When the divisor equals 1, the quotient equals the dividend; When the divisor is greater than 1, the quotient is less than the dividend. But in fact, the meaning of fractional division and integer division is the same, that is, the product of two factors is known, and one factor is used to find the other factor. Dividend numerator multiplied by divisor denominator, dividend denominator multiplied by divisor numerator.