The application of ratio is a common problem in primary school mathematics, which usually involves concepts such as ratio and percentage. To solve the application problem of ratio, we need to master certain skills and steps. Below we will explain the problem-solving skills and steps in detail.

Reading theme

First of all, we should read the stem carefully, and understand the background and known conditions in solving the problem. If the topic involves familiar concepts or life scenes, it can help you understand the topic better.

Find out the key information

Find key information in the topic, including known conditions and problems. Key information usually appears in the form of mathematical symbols or words, such as "Bi", "Zhan" and "etc".

mathematical modeling

According to the key information, a mathematical model is established. If the topic involves proportion, you can write a proportion formula; If percentage is involved, you can write the formula of percentage. Mathematical model can help you better understand the topic and solve the problem quickly.

Calculation result

According to the known conditions and mathematical models, the results are calculated. If percentages are involved, pay attention to the conversion of units.

Integrate answers

Finally, integrate the answers. Compare the calculation results with the known conditions and problems in the topic, and judge whether it conforms to the meaning of the topic. If the calculation result is inconsistent with the topic, it is necessary to re-examine the known conditions and problems in the topic or re-calculate.

Explain an example.

For example, a farm has three kinds of fruit trees, namely apple tree, pear tree and peach tree. The ratio of their numbers is 3:4:5. It is known that there are 25 peach trees. How many pear trees are there?

First look at the topic and make clear the known conditions and problems. There are 25 peach trees in the title, but the question is how many pear trees there are.

Second, find out the key information. The key information in the topic is the proportional relationship between the number of three kinds of fruit trees and the number of peach trees.

Then, establish a mathematical model. According to the key information, we can write a proportional formula: number of apple trees: number of pear trees: number of peach trees =3:4:5. Since there are 25 peach trees, we can write the proportional formula: 3x = 4y = 5x25.