Transcription of the first part of video demo :

Sample of quotation with discounts and additional tax:

12 items whose price is 5$ each
1 2 * 5 C=

15 items whose price is 6$, on which we perform a discount of 10% 
1 5 * 6 - 1 0 % C=

We perform an overall discount of 15%
* 1 5 % C= ±

At last, we add a tax of 18% and totalize
* 1 8 % C= T

Insert a row with 2 items whose price is 4$ each
2 * 4 C=

Modify a row
. 5 C=


Transcription of the second part of video demo :

Now, I am a mechanic and I practice two levels of hourly prices:
The first price is 15$ by hour
1 5 M=

The second price is 25$ by hour 
2 5 M=

I have to do a new quotation:

2 hours for the first price
2 * 15 C=

3 hours for the second price
3 * 25 C=

4 hours for the first price
4 * 15 C=

Calculate a tax of 18% and totalize
* 1 8 % C= T

A few days later the customer want accept quotation,
but the first level's price increased:

Now it is 17$ by hour
7 M=

the customer accept the new quotation and give an advance of one hundred dollars

Copy the result
208.86 C=

Record advance of 100 dollars and totalize
1 0 0 D= T