Decimal = sum ÷ (multiple+1) (decimals are generally used as standard quantities)
Large number = and-decimal or large number = decimal × multiple
Equivalence relation: decimal+decimal × multiple = sum
The problem of difference multiple is an applied problem to find the difference and multiple of two numbers.
Decimal = difference ÷ (multiple-1)
Large number = decimal+difference or large number = decimal × multiple
Equivalence relation: decimal × decimal = difference
The characteristic of the problem of sum and multiple is to use the sum of two numbers and their multiples to find out what the two numbers are. The best assistant to solve and multiply application problems is to draw a line graph to express the quantitative relationship between two quantities.
Extended data:
For example, "the red pencil is three times as big as the white pencil" means that the white pencil is multiple and the red pencil is three times. So we can set the white pencil as a multiple: X means that the red pencil is three times as large as the white pencil, and 3x means that "the sum of the red pencil and the white pencil is 64" means the number of red pencils+the number of white pencils =64 (total).
Solution: Let the white pencil be X (multiple), then the red pencil is 3x.
x+3x=64
4x=64
x = 64 \4
x= 16
Red pencil: 3x = 3x 16 = 48 (sticks)
A: There are 16 white pencils and 48 red pencils.
For example, a class bought several exercise books with a unit price of 0.5 yuan. If these exercise books are only given to girls, each person will get15 on average; If these exercise books are only given to boys, everyone will get 10 on average. Then, distribute these exercise books evenly to the whole class, and everyone should deal with:
Boys, on average, each person can get 10, which means there are more boys.
Girls pay 15*0.5=7.5 yuan.
Boys pay 10*0.5=5.0 yuan.
According to 15 10, the ratio of male to female is 3: 2. Girls account for 2/5 and boys account for 3/5.
[7.5*3/5+5.0*2/5]/ 1=6 yuan.
These exercise books are distributed to the whole class equally, and each person should deal with 6 yuan.
Unfortunately, the above calculation is wrong.
According to 15 and 10, the ratio of boys to girls is 15: 10. Suppose male 15 and female 10. The total number of books is 15× 10= 150.
0.5×150 ÷ (15+10) = 3 yuan. The correct answer is 3 yuan.
References:
Baidu Encyclopedia-Differential Times Problem
References:
Baidu encyclopedia-and the problems of the times