Step-by-step explanation:
Yes this is actually correct, labelling numbers gives it a meaning, and also makes it understandable to whoever is reading or solving a problem associated with the number
12+2=3 ordinarily would be false because
12+2=14
but when a label is attached
that is 12 inches + 2 feet= 3 feet
12 inches is the same as 1 foot
so 1foot+2feet= 3 feet
9 + 6 = 3 ordinarily is false as 9 + 6 = 15
but
√9feet + 6feet = 3yard
3feet + 6feet = 3yard