What is the secret of parenthesis and brackets? If you can't answer, don't answer indiscriminately.

Parentheses are used to round the number of additions or subtractions, such as 5+3+5+7 = (5+5)+(3+7) = 20;

27- 15-7-5=(27-7)-( 15-5)= 10

However, it should be noted that if the topic is one plus one MINUS, such as the topic: 30-4+ 16, it cannot be like: 30-

(4+ 16) If you put brackets like this, you must calculate from left to right according to addition and subtraction. This is a math problem.

Beware of common traps.

Subtracting brackets means taking them apart and rounding up the numbers. (If you are in the fourth grade, you can use addition.

Or subtract the exchange rate) for example: (35+4)+5=35+5+4=44.

Similarly, for questions like (35+8)-5, if you want to open the brackets, you must change the symbols in the brackets.

Number,+change-,-change+,can't be like this: 35-5+8, the correct one is like this: 35-8-5, and then add and subtract.

From left to right, remember: the minus sign should be changed before or after the brackets.

No, be careful, it's also a math trap.