After Weibo was issued, it immediately attracted a hot discussion from netizens. Netizens are very sure of their answers, but they are divided into two types. Someone answered 1 and someone answered 9. Regardless of the outcome, netizens are confident in their answers.
Some netizens think it is 1, because 2( 1+2) is a whole, and the result of the operation is 6, and then 6÷6= 1.
Some netizens think that according to the mixed algorithm of addition, subtraction, multiplication and division in primary schools, the result in brackets is 3, and the rest is multiplication and division. The algorithm stipulates that the same level of operation, from left to right, then the result should be 9.
The teacher gave the answer: 9.
Teacher Sun of the Mathematics Department of a university in Nanjing thinks that according to the order of mathematical operations, count the ones in brackets first, and then operate from left to right. The result must be 9, there is nothing to dispute.
Some netizens said that 2( 1+2) is a whole and unreasonable. Even if this multiplication sign is omitted, it should be counted from left to right.
Subsequently, the reporter consulted a junior high school math teacher again. According to the elementary school algorithm, this topic must be 9. Calculate 2+ 1 in brackets to get 3, and the rest is the same level operation. This problem is divided first and then multiplied, and the result is 9.
Teacher Yan said that many people think that taking 2( 1+2) as a whole is influenced by middle school textbooks. Middle school mathematics textbooks say that the multiplication of numbers and letters can omit the multiplication sign, and the combination of numbers and letters can be regarded as a monomial. But this topic is all numbers, no letters, so there is no monomial. Then, it is necessary to calculate the same level operation principle from left to right in brackets in strict accordance with the algorithm. The answer to this question is indisputable and must be 9.