Option 1: You have the ability to Select and Aggregate any History entry. CALC will also Auto-sum all numbers entered each day.
Option 2: In the Landscape Mode, you can swipe down (or tap & hold) the three dots in the upper left side, to reveal the "Tape-roll" mode, where you have the ability to do fast Sub-sums and Total sums. You can also turn history off temporarily so that you do not put all the intermediate entries into it.
Option 3: If you tap and hold the ANS button, you can switch it from last answer(s) into the more traditional M+/-R mode and use it like your were used to. One added benefit is that CALC will always display the running memory value in the top left (Tip) corner for your convenience.