Daily use of mathematics?

My husband and I were discussing the reasons why we learn tough mathematics in high school. 1 they want us to know these things to kind of manipulate us into being better people/more successful people. 2 we dont see a lot of the mathematics we use daily until we sit back and yze it. But he does hvac and has dont construction. What would be use the square root of a number for or anything likewise? Just curious.