In the recent Harvard Business Review article "The Science of Thinking Smarter" , molecular biologist John Medina discussed stress implications of neuroscience research, especially the impact on learning. When I read that stressed people do poorly at math, the NASA engineer in me asked what productivity insights we could learn from the those four familiar operations. For a bit of variety, I'm keeping this short (!), so please contribute your insights. Happy calculating!
"Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones." -- Arthur Conan Doyle
We want it all - information, opportunities, and results. Unfortunately, we are deluged with requests for our attention, and each time we say yes we're adding work to our already overloaded future selves. And because deep down we know how much work we have, each one increases stress. So should think very carefully before pressing the "+" key. Try this: For each request, ask whether it leads directly to completing an important project or furthering a major goal. If not, bite the bullet and say no. This has implications for information overload. Thinking of subscribing to a blog or podcast? Great! What are you going to give up for it? Or for filing: Is it really worth keeping this? It's likely you can find it again, that is, if you end up needing it all (usually unlikely).
Summary: Be careful when you add information or commitments to your life, and if you do, try to remove something else in exchange.
"Nothing can add more power to your life than concentrating all your energies on a limited set of targets." -- Nido Qubein
"+"'s twin is a powerful productivity tool. Shedding things from your life not only frees energy for other work, but opens up space for unexpected opportunities. Following are a few recycling bin candidates. First, boost energy and productivity by going on a media diet by cutting out TV and news. TV is mostly crap (sorry!) and news is rarely important or durable. Try this: Remove all news from your life for a week - radio, TV, papers, and web sites. I'd wager that very little of what you missed is still important now. And relax: You'll find out about big things from your people. Second, look for things on your To-Do list you could let go of with little impact. Ideal candidates are those stale ones you've been avoiding. Finally, remove distractions from work. When you sit down, clear your desk's "180" (the space in your field of vision), quit all the programs you can (email, IM, browser), put up your "Do Not Disturb" sign and dig in, one project at a time.
Summary: Look at the information and commitments you can remove from your life, and let them go. You might find that once you start throwing out "empty calories" from your life you'll get some welcome relief and makes physical or mental space for that which is more important, valuable, and richer.
"Opportunities multiply as they are seized." -- Sun Tzu
Multiplying is all about bang for the buck. Read Koch's "The 80-20 principle" to learn that most results come from a vital few activities, not the trivial many as expected. To multiply your work, automate (that is, multiply yourself) and eliminate (see above) so you can focus on the highest payoff work. Note that you'll have to analyze previous results to identify contributions. Other implications: For email, every message you send multiplies by attracting responses so send fewer. For clutter, anything you leave out will multiply like rabbits, so have a system to manage workflow. For your computer, every keystroke takes time, so use macros and shortcuts.
Summary: Focus on the few inputs that generate the most output, and cut down on things that generate negative work.
"Nothing is particularly hard if you divide it into small jobs." -- Henry Ford
To get productive with division, think slices and boundaries. To beat procrastination, break big jobs into small tasks - five minute ones if you're really stuck. To manage focus, carve your day into uninterrupted blocks of time (approximately one hour chunks), and concentrate on one project during them without multitasking. To leverage staff, outsource or delegate important tasks that you're not good at or don't enjoy. Finally, a major productivity opportunity is to divide your overall workflow into stages - Gather incoming into inboxes, Empty them to extract action, Plan your day and week, and Act on the plan.
Summary: Divide work and time into chunks, delegate as much as possible, and adopt a method to control your workflow.
-  The Science of Thinking Smarter: A Conversation with Brain Expert John J. Medina. Find his executive summary here.