The letters A, B, C, D, E, F, G and H correspond to the numbers from 0 to 7 with no repetitions.
Use the clues that A+C=A and F×D=F to find the values of two letters.
Use the clues A+H=E and E−G=F to find the remaining values.
This problem is adapted from the NRICH task Letter Land with permission of the University of Cambridge. All rights reserved.