To calculate the cost of several notebooks, you must know how much it costs to buy a notebook;

To know how many meters it takes to make several sets of children's clothing fabrics, you must know how many meters it takes to make a set of children's clothing fabrics;

The idea of finding out what the "single quantity" is from the known conditions of the application problem and then calculating what the required quantity is is called.

Normalize your thinking. This kind of application problem is called "normalized application problem", which is a kind of application problem that has been contacted since the third grade of primary school.

Such as type problem:

1, a lawn mower can mow 480 kilograms in 3 hours. At this rate, how many hours does it take to mow grass 1440 kg?

A toy factory can produce 524 toys in 4 hours. According to this calculation, how many hours will it take to produce 1572 toys?