Math question...

Yesterday a pretty gal who was my customer came to my shop and she buy about RM1000++ clothes…After that when she wan away and she asked me a math question...

The tips are:

A=1

B=2

I=3

O=4

E=5

U=6

L=7

V=8

C=9

D=10

Then she wants me to answer below question:

D-L=?

I+O=?

B*2=?

O*2=?

D-C+O=?

A+B+I=?

This is a very easy math question…But I calculate many times also dun know the answer meaning, who can help me to calculate this question…Thx a lot…