Ellis showed a subtraction problem, performed both using the traditional regrouping, or borrow-and-carry, algorithm and using an example from the common core. Here’s a screenshot of the two methods.

Simplest subtraction has been the decrease of the Reich’s Jewish population by emigration, deportation and death. Currently: In Germany—500,000 Jews minus 310,000 equals 190,000.

Python recently celebrated its 30th birthday, and pioneers of the language have been reflecting on its significance as an open source project.

But could a subtraction-by-addition principle also be at play? Has Tampa Bay’s litany of offensive weapons become a logjam, hampering the chance to develop any chemistry?