Because you divide integer 70 by integer 1000 which yields integer 0. Thus, it all works correctly.
code:
FormatNumber(70.0/1000,2)
formatnumber(cdbl(70)/1000,2)

will give you 0.07 as result because you now divide double 7 by integer 1000. This is all explained in section 'Expressions' fo the KiXtart Manual.
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There are two types of vessels, submarines and targets.