For a start, I had a problem with the title: at that age, boys have dropped the precious practice of adding fractions to their age.
If we reach 100, we're likely to revert to childhood proudly adding fractions to the numbers.
It is similar to finding the common denominator when adding or comparing fractions.
On a recent afternoon, Ms. Lee led a discussion of adding fractions with different denominators.
Integration is like we also have to add all the decimals and fractions in between as well.
Adding and subtracting fractions went well enough, so long as they had the same denominator.
Those of us who can add fractions will get 11/12; in a multiple choice test, 11/12 is the answer.
If calculators are allowed, the student would not have to know how to add fractions; most people cannot add 2/3 and 1/4.
Thus those who can add fractions and can easily perform straightforward arithmetic have a time advantage.
Knowing your times tables helps with algebra or adding and subtracting fractions.