How many of the natural numbers from 1 to 800 inclusive, contain the digit 6 at least once?
+36914 for the 600's there is 100 such numbers (600 THRU 699)
for each other 100 there are 20 such numbers (example 006 16 26 36 46 56 66 76 76 86 96 60 61 62 63 64 65 67 68 69)
000, 100, 200,300,400,500,700's
100 + 7 x 20 = 240 numbers have at least one 6
