How do people determine location and boundaries

A mixed number such as 7 1/4 can be converted to a decimal. It is implied that 7 1/4 is really 7 + 1/4 and that 7 = 7/1 therefore we are first adding the fraction 7/1 + 1/4. Since 4 is the denominator original fraction part we will use it as our common denominator. 7/1 * 4/4 = 28/4. Then, 28/4 + 1/4 = 29/4. 29/4 is 29 : 4 = 7.25.