Teaser 2938: Numerophobia

From The Sunday Times, 13th January 2019 [link]

In Letterland there are no numerals. They use the decimal system of counting just like we do but the digits 0-9 are represented by the first ten letters of the alphabet AJ inclusive but in no particular order. The following calculations are typical:

A + G = C
B × J = FH

What number is represented by ABCDEFGHIJ?

As stated this puzzle does not have a unique solution.