Number sum calculation 1, fractional multiplication: the meaning of fractional multiplication is the same as integer multiplication, and it is a simple operation to find the sum of several identical addends.
2. Calculation rules of fractional multiplication: fractional multiplication by integer, the product of fractional numerator and integer multiplication is numerator, and the denominator remains unchanged; Fractions are multiplied by fractions, the product of numerator multiplication is numerator, and the product of denominator multiplication is denominator. But numerator and denominator cannot be zero.
3. The meaning of fractional multiplication The meaning of fractional multiplication by integers is the same as that of integer multiplication, which is a simple operation to find the sum of several identical addends. Multiplying a number by a fraction can be regarded as finding a fraction of this number.
4. Fraction multiplied by integer: combination of numbers and shapes, and conversion.
5. Reciprocal: Two numbers whose product is 1 are called reciprocal.
Ratio and ratio 1, the basic properties of ratio: the first and last terms of ratio are multiplied or divided by a non-zero number. This ratio remains unchanged.
The nature of the ratio is used to simplify the ratio.
The ratio represents the division of two numbers; There are only two items: the first item and the last item of the ratio.
2, the difference between ratio and proportion
(1) Different meanings, item numbers and part names. The ratio represents the division of two numbers; There are only two items: the first item and the last item of the ratio. This is a contrast. Proportion is an equation, which means that two proportions are equal; There are four projects: two external projects and two internal projects. A: B = 3: 4 This is the ratio.
(2) The basic nature of ratio and the basic nature of proportion have different meanings and applications.
The nature of the ratio: the first term and the last term of the ratio are multiplied or divided by a nonzero number. This ratio remains unchanged.
The essence of proportion: in proportion, the product of two external terms is equal to the product of two internal terms. The nature of the ratio is used for the solution ratio. Connection: Proportion consists of two equal proportions.
The commonly used quantitative relationship is 1, and each copy × number of copies = total number; Total number of copies/number of copies = number of copies; Total copies/number of copies = number of copies
2, 1 multiple× multiple = multiple; Several multiples ÷ 1 multiple = multiple; Multiply/Multiply = 1 Multiply
3. Speed × time = distance; Distance/speed = time; Distance/time = speed
4. Unit price × quantity = total price; Total price/unit price = quantity; Total price ÷ quantity = unit price
5. Work efficiency × working hours = total workload; Total amount of work ÷ work efficiency = working hours
These are the knowledge points I compiled for the sixth grade. I hope I can help you.