Question

You should write numbers as numerals for:
a) equations and formulas
b) Years and eras
c) Money
d) age
e) measurements
f) All numbers must be spelled out

Answer 1

(f) all numbers must be spelled out

Answer 2

A simple rule for using numbers in writing is that small numbers ranging from one to ten (or one to nine, depending on the style guide) should generally be spelled out. Larger numbers (i.e., above ten) are written as numerals.