Reduction is a commonly used mathematical thinking method. In this way, new knowledge can be transformed into old knowledge, thus solving new problems. "Transforming thinking" is the most basic and important method in mathematical thinking methods. Understanding and mastering this method can solve many mathematical problems, and at the same time, it can also cultivate students' ability to transfer analogy and solve problems.

First, the application of transformation in primary school mathematical calculation

1, decimal multiplication is converted into integer multiplication.

2. Division with decimal divisor is converted into division with integer divisor.

3. Fractional division is converted into fractional multiplication.

4. Addition and subtraction of fractions with different denominators are converted into addition and subtraction of fractions with the same denominator.

5. Conversion of decimals, fractions and percentages in four operations.

Second, that application of transformation in the calculation of plane graphic area.

1, the parallelogram is transformed into a rectangle by frying, cutting, moving and splicing, and then the calculation formula of its area is derived.

2. Triangles and trapezoids are generally converted into parallelograms by splicing method, and their area calculation formulas are derived. (Of course, you can also convert triangles into rectangles, and trapezoid into parallelograms, rectangles or triangles. By cutting and spelling, you can derive their area calculation formulas, which is an expansion of the teaching content of textbooks and is relatively difficult. )

3. By cutting and spelling, the circle is transformed into an approximate rectangle or parallelogram, and the formula for calculating its area is derived. It is also a challenge for students to convert a circle into a triangle in a certain way and deduce the formula for calculating the area. )

4. Cut the circular scissors into an approximate trapezoid and push down the area calculation method. For students, it is difficult and not easy to understand, and it is suitable for math activity classes. )

Third, the application of transformation in the volume calculation of three-dimensional graphics

1, the cylinder is transformed into an approximate cuboid by cutting and splicing, and the volume calculation formula is derived.

2. Convert the cone into a cylinder with equal bottom and equal height, and derive the volume calculation formula.

3. Convert irregular shape into regular shape and calculate the volume.

Fourth, the application of transformation in solving practical problems

For example, there are 45 students in Class One of Class Four (2), of which the number of boys is five quarters of the number of girls. How many boys are there? Divide the number of girls into five, four boys and nine in the class. In this way, the number of boys accounts for 4/9 of the class, and then the number of boys can be calculated.

Transformation is a strategy to solve problems, which essentially takes "retreat" as "advance", "retreat" as a means and "advance" as an end. Transformation thought is not only used in primary school mathematics, but also often used in middle school mathematics. Therefore, we should pay full attention to the role of conversion in teaching materials, so that students can learn this mathematical thinking method initially, constantly cultivate their thinking ability and improve their mathematical literacy.