April 20, 2022 15:28 GMT+7
After entering Primary School, students will be familiar with Mathematics. At the primary level, children are only exposed to simple knowledge such as addition, subtraction, multiplication and division. Gradually, the knowledge will be increased in difficulty, not only applying the usual formula but also having to practice thinking and logical thinking.
A parent in China was very upset recently when his son’s 5 x 6 = 30 math problem was incorrectly graded by his teacher and given 0 points. Looking at the problem over and over again, he didn’t understand where his son did wrong and why he lost points so absurdly. Too frustrated, this parent called to question the teacher and received an unexpected explanation.
According to the teacher, the topic has the following content: “Tieu Le and 5 classmates ride the train together, each person 5 VND. How much money in total?”. The key in the problem is the data “Tieu Le and 5 classmates”, so the correct calculation should be (5 + 1)x 5= 30. After hearing this explanation, the parent also understood.
In fact, this isn’t the first time parents have argued over seemingly simple elementary math problems, but they’re actually extremely wacky. There used to be many Math problems that gave trap data, requiring students to think logically and read the question carefully to get the correct answer.
For example, the following Math problem: “If you take 100 yuan to buy something worth 35 yuan, how much change will you get back?”. Student answered “100 – 35 = 65” but she crossed it wrong. The teacher then explained:
“There are three other situations that the student hasn’t thought of. First, if there are two 50-yuan bills, then we just need to take out one 50-yuan bill and pay for it and receive 15 yuan change. If there are five 20-yuan bills, then take two 20 yuan bills to buy things and get 5 yuan change in return If there is one 50 yuan bill, one 20 yuan bill, two 10 yuan bills and two 5 yuan bills, then just take one 20 yuan bill, one bill 10 yuan and a 5 yuan note to pay. In this case, there is no need to take back the change.”
Or Math problem: “It takes 6 minutes to saw a log into 3 pieces, according to this calculation, how many minutes does it take to cut into 5 pieces?”.
Normal thinking would surely be, 3 segments of 6 minutes, 1 of 2 minutes, sawed into 5 segments is 5 X 2 = 10 minutes. However, the right thinking should be: A wooden bar only needs to be sawed twice to be cut into 3 segments, and only needs to be sawed 4 times to be sawed into 5 segments. 3 segments 2 saws but took 6 minutes, which means sawing each segment takes 3 minutes, not 2 minutes as the students inferred.
Thus, to saw 5 segments, it takes 4 saws, with each saw 3 minutes. The correct answer is: 6 ÷ (3-1 ) × (5-1) = 12.
According to phapluat.suckhoedoisong.vn
at Blogtuan.info – Source: infonet.vietnamnet.vn – Read the original article here