Some custom CSS is used to tweak the looks of the above "Matrix". Check with the Designer to see what is going on. There are some comments to help guide you with further tweaking of the looks.
JotForm is quite powerful for those who want to adventure beyond the standard/normal use.
The CSS in this exemples does :
varying the size of the column headers
bolds the column and row headers
changes the size of a column and a row, additive effect of cell at crossing point
removes (hides) two options of first cell's drop down menu
removes (hides) content of some cells
changes colors of various sub-elements
adds day number (!) in the upper left 'corner' of cells
Of course, one would probably not do all of those things to a single grid. This is just to show what can be done with a bit of creative CSS tweaking. You could just do the grid/matrix and leave things as they come by default and make your life simpler ... but the grid boring to the users of your form.
The running total uses the 'numerical text' found at the lowest level. Here, the options of the drop down used for the cells includes the 'cost'. Note that the cells could be defined as a radio button (no text) and then the title of the columns is used to find 'numerical text' which becomes the values. It's odd and ... cool at the same time. I did not manage to use the 'calculated values' within the matrix definition. Those seemed ignored no matter what ... I kind of like how it works with the 'numerical text' taken from options or titles. The only catch is you can't use numbers in those fields. If you have "1/2 day AM (13$)" the value becomes 1213 !! If you have ".5 day AM (13$)" the value then becomes 0.51 (probably 0.513, but only displays two decimal places).
There are limitations but that's half the fun of programming ... to figure just how far one can take it. ;)
With "Matrix" I have not found a way to control the number of options to display at once - it is not part of the CSS 'style'. To manage the column width, one seems to have to play with font-size of nth-child.
Ideally, JotForm will eventually parametrize such an advanced "Matrix" element to make it much easier for all to integrate in their forms. Until then, roll up your sleeves and dive into the Custom CSS feature of Designer.