1. Provides a sales invoice frame by drawing lines on the cells shown in Figure 2.
2. Incorporate sales invoice data by typing the labels and values on the cells shown in Figure 2.
3. Calculates sales invoice data with the following formulas:
a) E11: +C11 *D11
b) E12: Copy from E11 to E12.
c) E13: @sum (E11.E12)
d) E14: +E13*0.10
e) E15: +E13-E14
