User-Defined Keys

Any part of an expression in the history or build displays that can be touched and copied can also be touched and dragged to one of 10 user-defined keys. Tapping that key then inserts that expression part at the location of the cursor in the expression you are currently building.

Save special constants, groups of units and constants, advanced functions you use frequently, common unit conversions, important results from previous calculations, etc. Even entire expressions like graph specification forms can be saved.