All three apps are available for free in the Windows Store on devices running the Windows 10 Technical Preview. As with their iOS and Android counterparts, the apps are free, but access to the full set of editing features requires signing in with an Office 365 subscription.
Tapping the File menu opens Backstage view, which looks nearly identical to its counterpart in the corresponding desktop program. Recently edited documents appear in a column on the left; templates for creating new documents appear on the right.
Not surprisingly, you'll find fewer commands in these apps than in their desktop counterparts. Formatting and other options are arranged in the familiar ribbon, with additional options typically available in drop-down lists like this one.
In the Windows 10 tablet app, multiple authors can work on the same document simultaneously. With the Track Changes option enabled, everyone can see changes and add comments.
Signing in to an Office 365 account accomplishes two goals: it unlocks the full range of editing features, and it makes OneDrive and OneDrive for Business available as locations for creating new files.
The stripped-down Excel app has the full range of formulas available for adding and editing in spreadsheets. Note the oversized OK and Cancel buttons as wells as the categorized list of functions from which you can select a formula with placeholders for arguments and options.
As in the desktop version of Excel, you can drag (in this case with a finger or stylus rather than a mouse) to select a range of data. Then insert a chart and choose a type, layout, and style.
Formatting cells manually is tedious work on the desktop. It's even less fun on a tablet, which is why cell styles, shown here, are such a useful option.
All three apps fit neatly into Microsoft's"mobile first, cloud first" vision. You can sign in with multiple OneDrive and OneDrive for Business accounts and then create new documents, spreadsheets, or presentations in any of the connected locations. The app listings say that Dropbox is supported as well, but at least in this release I couldn't find a way to connect the apps to a Dropbox account.
You can add notes to any PowerPoint slide by switching to Notes view, as shown here. At least in this release, the touch-friendly tablet app doesn't offer a presentation view that allows the notes to be seen by the presenter.
It's relatively easy to add a new slide in the Windows 10 version of PowerPoint. Layout options include the same selections as in the desktop program.
When delivering a presentation, you can press and hold on the screen to make this virtual laser pointer available, dragging to simulate the effect of pointing at the screen to highlight options for an audience. Swipe from the top to make inking tools available for drawing and writing on a slide.
As with their desktop counterparts, all three of the tablet-friendly Office apps allow you to insert a picture into a document and then crop it. The selection of ready-made styles allows you to add borders.