دوتا ۴ ضلعی خوشگل

 ۱x 8 + 1 = 9
                     12 x 8 + 2 = 98                     123 x 8 + 3 = 987
                   1234 x 8 + 4 = 9876
                  12345 x 8 + 5 = 98765
                 123456 x 8 + 6 = 987654
                1234567 x 8 + 7 = 9876543
               12345678 x 8 + 8 = 98765432
              123456789 x 8 + 9 = 987654321
        
 ۰x 9 + 8 = 8
  ۹x 9 + 7 = 88                      98 x 9 + 6 = 888
                    987 x 9 + 5 = 8888
                   9876 x 9 + 4 = 88888
                  98765 x 9 + 3 = 888888
                 987654 x 9 + 2 = 8888888
                9876543 x 9 + 1 = 88888888
               98765432 x 9 + 0 = 888888888
              987654321 x 9 - 1 = 8888888888
             9876543210 x 9 - 2 = 88888888888