Rounding problem at 4 decimals

[sangland2]

Can anyone please explain why

round(223.435 *(1.15) , 0.0001) = 256.9503 (correct answer)

But

round(223.435 *(1+0.15) , 0.0001) = 256.9502

Also with a variable set to 1.15

round(223.435 * (num(vGSTMultipy,0.01)) , 0.0001) = 256.9502

But

round(223.435 * if(vGSTMultipy ='1.15',1.15,vGSTMultipy) , 0.0001) = 256.9503

[swuehl]

Please have a look at

Rounding Errors