They way I would do it other than with a calculator would be
27 x (90 - 0.5) which is the same as 27 x 89.5
=> 27 x 90 - 27 x 0.5
27 x 90 is (3 x 9) x 90 or 3 x 9 x 90
9 x 90 = 810
3 x 810 = 2430
Then subtract 27 x 0.5, or 27 / 2
2430 - 27 / 2
=> 2430 - 13.5
= 2416.5
Final answer:
2416.5
Hope I helped :)
