Convert 42 to a Roman numeral given that I=1, V=5, X=10, L=50, C=100, D=500, and M=1,000

We start with a total letter value of 42 that we want to work backwards with each letter until 0.

We want to build a Roman numeral term letter by letter as well, starting with nothing.

Dividing our current quantity of 42 by each Roman numeral Value, we need 4 of X

Since we want 3 or less of a letter, we need to do subtraction by writing the next letter of L in front of X

We piece that together with our Roman numeral(s) term of to get: + XL = XL

Since we needed 1 of the letter X and 1 of the letter L, our total value of letters becomes: 50 - 10 = 40

Our new decreasing total now becomes: 42 - 40 = 2

Dividing our current quantity of 2 by each Roman numeral Value, we need 2 of letter I

We piece that together with our Roman numeral(s) term of XL to get: XL + II = XLII

Since we needed 2 of the letter I, our total value of letters becomes: 2 * 1 = 2

Our new decreasing total now becomes: 2 - 2 = 0

Since our decreasing total now equals 0, we have our answer of