The solution is as follows

According to the topic, we can establish the following inequality: 80× x

Using the mathematical equation, we can express it as: 80x.

Now we need to solve this inequality and find the value of X.

The calculation result is: x=3, so in order to make 80× x

Extended data

Primary school mathematics is to teach children a series of knowledge about number, four operations, the calculation formula of figure and length, unit conversion and so on through textbooks, which lays a good mathematical foundation for junior high school and daily life calculation. Frieden Noel, a Dutch educator, said: "Mathematics comes from reality and must be rooted in reality and applied to reality."

Indeed, modern mathematics requires us to observe the world from a mathematical perspective and explain the world in mathematical language. Judging from the mathematics learning psychology of primary school students, the learning process of students is not a passive absorption process, but a reconstruction process based on existing knowledge and experience.

Therefore, learning while doing and learning while playing will make children learn more actively. From our educational goal, while imparting knowledge, we should pay more attention to cultivating students' comprehensive ability of observation, analysis and application.

Key points of knowledge

count

Integer, natural number, positive number, negative number, fraction, decimal number, percentage.

Counting units and numbers

Counting units, numbers and decimal counting methods.

Digital rewriting

1, directly rewrite multiple numbers into "ten thousand" and "hundred million";

First, move the decimal point of the original number to the left by 4 or 8 places (the end of the decimal part is 0 to be crossed out), then add 10000 or 10000 million, and add "=" in the middle.

Omitted mantissa is rewritten as a divisor: the mantissa after 10,000 digits or 100 million digits is omitted by rounding, and then 10,000 digits or 100 million digits are added after the number to obtain a divisor, and the middle is connected by "√".

2. Find the decimal approximation.

According to the requirements, wherever decimal places are reserved, the mantissa after this digit should be omitted by rounding, such as 1.5 ≈ 2, 1.4 ≈ 1. Use ""in the middle.