After learning twelve volumes of practical problems, many students now keep the infinite results of practical problems to integers. How to keep them? Whether to use the "one-in method", "mantissa method" or "rounding method" is often at a loss. According to my analysis and understanding, it is usually the number of iron sheets to be used when making buckets, so the "one-step method" is used. Because when you make something, you must also count the rest, that is, 3.0 1 square meter, and you should also increase it by 0.0 1 to leave 4 square meters, otherwise it will not be done well without enough iron sheets, and it will be inferior. You might as well not do it.

As the name implies, the "tail removal method" is to remove all the rest. For example, a bucket can hold 2.9 liters of water, so you should keep 2 liters. If you keep 3 liters, the water will be full. If it is full of oil, it will be all over the floor, and it will be very troublesome and wasteful to clean up.

For example, if there is a pile of sand and the result is to keep an integer, then use the "rounding method". If a pile of sand weighs 9.4 tons, it is necessary to keep 9 tons; If a pile of sand weighs 9.9 tons, it will eventually remain at 10 tons. So the rounding method will be more accurate.

Of course, the same is true of keeping integers in our daily life: generally, we use cents when we buy things, but now people don't have a penny or two, so sellers have to round them off. Rounding means removing the mantissa from 1 to 4, and moving from 5 to 9 to "1". For example, a catty of vegetables costs 54 cents, so a catty of vegetables can only sell for 5 cents, because it is 4 cents, so give up; If a catty of vegetables sells for 55 cents, then a catty of vegetables can sell for 60 cents. Because it is 5 cents, it should be "1".

So students won't worry about the word "reservation".