Mom Circle
Ask your child to choose a topic that he or she thinks is meaningful.
Fill in the blanks. 4. The function of parentheses is to change the order of calculation.
5. This question can be concluded by comparison.
8. Hint: The difference between the subtraction is the subtraction, that is, the subtraction is 2 180.
10. List these 4 numbers into an equation by addition, subtraction, multiplication and division and borrowing parentheses, so that the result of the equation is 24, which is a game that many parents played when they were children. There is no single answer to this question. Such as 5 (4 2) x8, 4 5 8 2, (8 5) 2x4 ,......
Judgment section. 2. Addition and multiplication are outside the brackets, and multiplication is calculated first and then added. The calculation order of the problem formula is first subtracted, then multiplied and then divided.
3. After adding parentheses to equation 2, the subductive number becomes larger than equation 1, so the numbers are not equal.
Select the section. 1. Subtraction is subtracted by difference.
2. Through comparison, it is found that the result of the equation remains unchanged after removing the parentheses.
Calculation section. There are parentheses, first count the inside of the small brackets, then the inside of the middle brackets, and finally the outside of the brackets.
Combine formulas to determine whether parentheses and middle parentheses need to be added according to the calculation order.
Work something out. 4. The results of the two schemes can be calculated separately and then compared. (1) Option 2 is cost-effective. (2) Plan 1 is cost-effective.
Thinking Boost. If you make a mistake, you can push back the unknown number through the wrong formula, and then list the correct formula to calculate the result.