BATTLING TO WORK OUT HOW MUCH TO CUT

Hi everyone ,

i am about to start my taper .realy nervous.

I am on 10.5 bromazepan,they come in 3mg and i take 1 in the morning .1 in the afternoon and 1 and a half at night  total 10.5  how do i work out 1/8 the of that ,do i just devide the total by 8  and how would i do it if i wanted to do 5%  .maths was never my strong point  .