I need some help with this formula

copy and past from Excel

steel actual deflection 0.15mm

0.001*0.4³/48*207000000000*5.316759994E-11=1.52mm

brass actual deflection 0.26mm

0.001*0.4³/48*105000000000*4.935823594E-11=7.18mm

0.002*0.4³/48*105000000000*4.935823594E-11= 1.43608E-05

I have to work out the theatrical deflection for steel and brass loads from 0.001 to 0.005N. My calculations for steel are close to actual, but for brass 0.001N load deflects more then 0.002N load. Calculation are done on excel as my calculator shows sentex error :?

Any help will be appreciated.