Sunday Times Teaser 2901 – Square Deal

by Danny Roth

Published April 29 2018 (link)

George and Martha have five daughters who have periodically appeared in my teasers over the years. They are all working for the same company and have perfect-square four-digit telephone extensions, in all five cases. The letters ABCDEFGHIJ stand for the digits 0-9 but in no particular order. The extensions are as follows:

Andrea  IBHC

Bertha  DJJC

Caroline  BAFH

Dorothy  GFID

Elizabeth  GAEE

What are the five extensions?