First, the calculation rules of fractional multiplication:
1, Fraction multiplied by integer: the product of numerator multiplied by integer is numerator, and the denominator remains unchanged. (Integer and denominator divisor)
2. Fraction and fractional multiplication: use the product of molecular multiplication as the numerator and the product of denominator multiplication as the denominator.
3. In order to simplify the calculation, the points that can be reduced are reduced first and then calculated.
Second, the law: (when the multiplication is relatively large)
1, a number (except 0) times a number greater than 1, and the product is greater than this number.
2. A number (except 0) multiplied by a number (except 0) is less than 1, and the product is less than this number.
3. A number (except 0) is multiplied by 1, and the product is equal to this number.
3. The commutative law, associative law and distributive law of integer multiplication are also applicable to fractional multiplication:
1, multiplicative commutative law: a× b = b× a.
2. Multiplicative associative law: (a×b)×c=a×(b×c)
3. Multiplication distribution law: (A+B) × C = AC+BCAC+BC = (A+B) × C.
Fourth, the method of finding the reciprocal:
1, find the reciprocal of the fraction: exchange the position of the denominator of the numerator.
2. Find the reciprocal of an integer: treat the integer as a fraction with a denominator of 1, and then exchange the positions of the denominator of the numerator.
3. Find the reciprocal of the band score: turn the band score into a false score, and then find the reciprocal.
4. Find the reciprocal of decimals: Turn decimals into fractions, and then find the reciprocal.
Verb (abbreviation for verb) surface area:
1, triangle area = base × height ÷2. The formula S=a×h÷2.
2. Square area = side length × side length formula S=a2
3. area of rectangle = length× width formula S=a×b
4. area of parallelogram = base× height formula S=a×h
5. trapezoidal area = (upper bottom+lower bottom) × height ÷2 Formula S=(a+b)h÷2