Calc+

☆First, register formula, then input number.

☆And other function llike excel's "vlookup" function and "if" statement.
Please check image.

☆please tap right up button on display. You can select menu.

☆If you use "Range", you should care term order.
Term judge from up to down.

If you want to below

score 80 over → grade 5
score 50 over → grade 3
score 30 over → grade 1
else → grade 0

you should set below

default:0
80 <= value:5
50 <= value:3
30 <= value:1

Don't you set below
30 <= value:1
50 <= value:3
80 <= value:5

order is important

☆protect mode
once save formula, you can select protect mode.
protect mode is forbid to edit formula and invisible consant, select type and range type's second value.
you can concentrate to input