multiply two coloum values display in textboxs

Question

if sql table like below

sno qunty rate
1      5      6
2      4      3.5

multiply coloum2 and coloum3
i have two textbox1,2

read
first textbox,second text box dispaly like ( qunty * rate )5*6= 30
firsttextbox=30,secondtextbox=14

o/p like

30
14