It is mentioned that a factory planned to produce 12600 kg last year, but completed one-ninth of the annual plan in the first half of the year. We need to find out what happened in the second half of the year.
According to the information given in the title, we can make the following reasoning:
The annual planned output is: 12600 kg.
The output in the first half of the year is:1/9×12600 =1400 kg.
The output to be completed in the second half year is:12600-1400 =11200 kg.
According to the above reasoning, we can draw the conclusion that the factory planned to produce12600kg last year, and completed1400kg in the first half of the year, and should complete11200kg in the second half of the year, thus completing the annual production plan.
But there is a problem here: the "one ninth" mentioned in the title should be one ninth, not one ninth. So in fact, the production capacity completed in the first half of the year should be:1/9×12600 =1400 kg.
Methods of calculating mathematical problems:
1, direct calculation method: for simple math problems, you can directly calculate according to math knowledge. To find the sum or difference of two numbers, you only need to add or subtract these two numbers to get the result.
2. Formula method: There are many formulas in mathematics that can be used to solve different types of problems, such as trigonometric functions, exponents and logarithms. If the problem involves these formulas, you can directly use the corresponding formulas to calculate.
3. Reasoning method: For some problems that need to be reasoned, the results can be deduced step by step through known conditions and reasoning rules. In geometry, we can prove some propositions with properties such as parallel lines and vertical lines, and then draw other conclusions from these propositions.
4. Image method: For some geometric or algebraic problems, you can draw pictures to help you understand the problems and find solutions. Mirror image method can intuitively express quantitative relations or geometric shapes, which is helpful to simplify problems and find solutions.