For example, reverse thinking, that is to say, if the title says 16 plus how much is equal to 20, then subtraction is 20- 16, and then the unknown number can be found. For another example, if the title says 5 times what equals 25, then divide by 25/5 and you can find the unknown number. In fact, the so-called reverse thinking means that the topic says you add and subtract, and the topic says you multiply and divide, okay? The opposite of reverse thinking is equation, and equation is positive thinking. General formulas are based on reverse thinking.

Hit it by hand, QAQ, hope to adopt it