Why it is 8.50 not 8.30
An hour has 60 minutes. 30 ÷ 60 = 0.50. If you write 8.30, payroll thinks you worked 8 hours and 0.30 × 60 = 18 minutes.
What is 8:15 in decimal? 8.25 (15 ÷ 60 = 0.25).
What is 8:45 in decimal? 8.75.
What is 7 hours 45 minutes in decimal? 7.75.