1, additive commutative law: a+b = b+a; Additive associative law: a+b+c=a+(b+c).

2. Number of copies × number of copies = total number of copies, total number of copies = number of copies, total number of copies = number of copies.

3. 1 multiple × multiple = multiple, multiple1multiple = multiple, multiple/multiple = 1 multiple.

4. Speed × time = distance, distance/speed = time, distance/time = speed.

5. Unit price × quantity = total price, total price/unit price = quantity, total price/quantity = unit price.

6. Work efficiency × working hours = total workload, total workload ÷ work efficiency = working hours, total workload ÷ working hours = work efficiency.

7. Appendix+Appendix = sum, and-one addend = another addend.

8. Minus-Minus = difference, Minus-Difference = Minus, Difference+Minus = Minus.

9, factor × factor = product, product ÷ one factor = another factor.

10, dividend/divisor = quotient, dividend/quotient = divisor, quotient × divisor = dividend.

1 1, perimeter of square c, area of square s, side length of square a, perimeter = side length× 4, C=4a, area = side length× side length, and s = a× a.

12, cube v: volume a: side length, surface area = side length× side length× 6, s table =a×a×6, volume = side length× side length× side length, and v = a× a× a.

Math learning skills in the fourth grade:

1, combining learning with thinking:

In the process of learning, we should carefully study the contents of textbooks, ask questions and trace back to the source. For every concept, formula and theorem, we should understand its context, cause and effect, internal relations, and mathematical ideas and methods involved in the derivation process. When solving problems, we should try our best to adopt different ways and methods, and overcome the rigid learning methods of books and machinery.

2, the combination of learning and application, diligent in practice:

In the process of learning, we should accurately grasp the essential meaning of abstract concepts and understand the evolution process of abstraction from actual model to theory; For theoretical knowledge, we should seek its concrete examples in a wider scope, make it concrete, and try our best to apply the theoretical knowledge and thinking methods we have learned to practice.

3, want to take, be bo back:

Textbooks are the main source of students' knowledge, but they are not the only source. In the process of learning, in addition to studying textbooks carefully, we should also read relevant extracurricular materials to expand our knowledge. At the same time, study hard on the basis of extensive reading. Master its knowledge structure.

4, both imitation and innovation:

Imitation is an indispensable learning method in mathematics learning, but it must not be copied mechanically. On the basis of digestion and understanding, use your brains and put forward your own opinions and opinions, instead of sticking to the existing framework and existing model.

5, review in time to enhance memory:

What you learn in class must be digested on the same day, reviewed first and then practiced. Review must be carried out frequently, and after each unit, the knowledge learned should be summarized and sorted out to make it systematic and profound.