Practicing Olympic Mathematics every day in the sixth grade of primary school: an interesting math problem

Xiaoming lives in an alley. One day, he worked out the house number of this alley. He found that getting rid of himself

Not counting home, the sum of other house numbers is exactly 100. Excuse me, there are _ _ _ _ households in this alley (that is, how many households?

A house number). Xiaoming's house number is _ _ _ _ _.

answer

There is only one specific numerical value of this topic, so it is necessary to solve the problem by estimation! We all know:

1+2+…+ 10=55, so it should be 1 ~ 14 or 1 ~ 15.

(1)1+2+…+14 =105, Xiaoming's house number is 5, * * has14 households;

(2)1+2+…+14+15 =120. Xiaoming's house number is 20, which is no longer in the range of 1 ~ 15, which does not meet the meaning of the question.