The naughty family ordered 3 bags of pure milk every day in September, and paid a total of 85.5 yuan at the wholesale price. How much cheaper is each package than the retail price? Retail price 1. 1 yuan. So each package is 0. 15 yuan cheaper than the retail price.

How many days are there in September? September =30 days.

85.5 lbs (30x3)

=85.5÷90

=0.95 yuan

1.1-0.95 = 0.15 (yuan)

A: It's 0. 15 yuan cheaper than the retail price.

analyse

This topic examines fractional division and subtraction.

Since there are 30 days in September, the number of days in September is multiplied by 3, and it is found that the naughty family ordered 30x3=90 bags of milk in September. Then, according to the unit price = total price ÷ quantity, divide 85.5 by the number of milk bags booked by naughty bag in September, and find out that the preferential price of each bag of this milk is 0.95 yuan.

Finally, the retail price of each bag is used to subtract the preferential price of each bag of this milk, which is lower than the retail price1.1-0.95 = 0.15 (yuan).

Extended data:

Elementary arithmetic order:

1, same level, from left to right;

2. Two-stage operation, first multiply and then divide, then add and subtract. ?

3. When there are brackets, count the inside of brackets first, and then count the outside of brackets;

4. When there are multiple brackets, count the brackets first, then the brackets inside, then the braces inside, and finally the brackets outside.