Welcome to the world of floating point arithmetic! See this link:
Bottom line ... 0.94 cannot be represented exactly in IEEE double precision. That trailing 1 is actually part of more digits in an exact floating point binary to decimal conversion:
>> fprintf('%.60f\n',0.94-1)
-0.060000000000000053290705182007513940334320068359375000000000
The 0.94 all by itself converted into decimal is:
>> fprintf('%.60f\n',0.94)
0.939999999999999946709294817992486059665679931640625000000000
