[d-sc]

2 * 4 = 8 so the last significant digit should be an ‘8’

[pjc50]

Definitely one to cite in the "overreliance on calculators" - the comment you are replying to should have realised that multiplication can't create digits to the right like that!

(Most desktop calculators do it in BCD which would give the correct result, too)

[mark-r]

I use Python as my desktop calculator. It has a Decimal module that would have gotten it correct, but that would have been way too much trouble.