I agree. Knowing some things by rote is essential for the practical ability to estimate answers to problems quickly and/or recompose math problems as simpler co

I agree. Knowing some things by rote is essential for the practical ability to estimate answers to problems quickly and/or recompose math problems as simpler components. For example on my way to work at the 14th station I wanted to know how many blocks walk it was to the office on 33rd. I know that 14 is close to 15, and 33 is close to 30, and I know that 15 + 15 is 30. So this allows me to quickly recompose the problem as 1 + 15 + 3 = 19, which gives me the answer practically instantly with no calculator or manual math mechanics required. This wouldn't be possible without knowing that 15 is half of 30.