Discover your intellectual strengths

This month's issue:

- Puzzles and Teasers
- Article: Nutrition and the Brain
- Quotes and trivia
- Book Review - Match Wits with Mensa
- Word of the month
- Latest news and developments

Name the most recent year in which New Year's preceded Christmas.

Two girls are born to the same mother, on the same day, at the same time, in the same year and yet they're not twins. How can this be?

What word or expression is represented below?

GIVE, GIVE, GIVE, GIVE, GET, GET, GET, GET

By Steven Gillman

I had my own math shortcuts when I was a child. Using these meant that I didn't "show my work" in math class, as was required. This annoyed many of the teachers, and lowered my grades. I did get the correct solutions to my math problems, however. I was simply using different algorithms, ones which I had a hard time expressing on paper.

In my thinking, for example, 97 x 16 became 100 x 16 (1600) minus 3 x 16 (48). It was easier that way, and thinking this way became almost automatic. As a result, I might just write down 1552 even though I couldn't explain very well how I arrived at the answer. My teachers called that a problem, but many years later such math shortcuts were being sold in seminars and books.

You can make your own math shortcuts. The following may give you some ideas on how to do that. Alternately, you can try any of the shortcuts and algorithms you read about and adopt the ones that are best suited to you. There are no perfect techniques for all people, because our minds work in slightly different ways.

For example, suppose you want to multiply 68 x 6. My mind immediately thinks "60 x 6 = 360 and 8 x 6 = 48, and 360 + 48 is 408." That is one way to quickly arrive at a solution without pen and paper. It is essentially this: (60 x 6) + (8 x 6) = 408.

Want another way? Think of it as (70 x 6) - (2 x 6). The "internal dialog" might be something like this: "70 x 6 = 420, but that is two "sixes" too many, so take away two sixes (12) and I have 408." The point is that there is often more than one way, and you can use whichever math shortcut is easier for you.

If the problem was 68 x 9, by the way, my mind immediately focuses on the 9. Why? Because it is close to 10, and multiplying by 10 is easy. 68 x 10 is 680, from which I just have subtract the extra 68 to arrive at the solution of 612. Always look for the numbers that are close to 10 or 100 or 1000, and you'll find the easier way to do the math, especially if you are trying to do it in your head.

Percentages can be trickier to do as mental math, but there are ways. Suppose, for example, that you want to figure what the 4.6% sales tax will amount to on your $29 book. One quick way to estimate it is to take 10%, or $2.90, cut that in half to arrive at 5%, or $1.45, and then just guess at around $1.35, because you know 4.6% is a little less than 5%. Alternately, you could think of 5% as a 20th of the price - if this is easier - and then round that figure down a bit.

What if you want a more precise solution? 1% of $29 is easy to arrive at (.29), so multiply that by 4 to arrive at $1.16. (You might think of this as (4 x 30) - 4.) Now you just need to add .6% to that. Think 6 x 29 = 174, and then put the decimal in the right place: .174. Add that .18 (round it up as the store will likely do) to the 1.16 and you have $1.34 in sale's tax, pretty close to our quick estimate. This is not as difficult as it might seem once you practice these shortcuts a bit.

Wit is educated insolence. - Aristotle

Character is higher than intellect. A great soul will be strong to live as well as think. - Ralph Waldo Emerson

A message for action travels from your brain to your muscles as fast as 250 miles per hour.

Studies show that IQ is modestly related to the speed at which you do some pretty simple things such as comparing two lines to see which is longer.

Wine drinkers on average have a higher IQ than beer drinkers. Studies show a slight advantage to wine drinkers — but do wine drinkers have higher IQs because they drink wine or vice-versa ? It may be that some people with high IQ reach a high social status and then choose to drink wine to fit in.

Evince

To show in a clear manner; to manifest; to make evident; to bring to light.

Though his earliest tales are little more than quick, offhand sketches seasoned with slapstick humor, his mature stories evince the psychological complexity and atmospheric detail that distinguish his best-known plays. -- "Quick Trips Through the Imagination", New York Times, July 12, 2000

Suppose you've run out of milk, and you decide to make a quick trip to the grocery store. On the way there, you think of several more things you need. You reach the store, spot a few bargains, and fill your cart. Then you return home, and realize that you forgot to buy the milk you needed in the first place.

There's a simple and effective way to avoid this kind of memory lapse: give your brain a break, and make a shopping list.

On any given day, dozens of things compete for your attention and your memory capacity. Sometimes the smaller details simply get crowded out. The result is often minor forgetfulness. In many cases, the problem is just an overtaxed memory.

Your shopping list will do your remembering for you, and free you up to focus on other things. But relying on lists does not mean you have become "over the hill." As evidence that the details of modern life have exceeded the memory skills of many people, young and old, consider the explosion in popularity of palm-sized computers called personal digital assistants. Without these memory aids, many of the most competent, accomplished people in the world would regularly run out of milk and forget to pick up their dry cleaning.

But you don’t need a computer to boost your memory abilities. All you need is a notepad, or a small notebook. Next time you're planning a quick trip to the store, take a few moments to jot down a list of the items you need while it's still fresh in your mind. Later, you won't come home without the milk. Of course, you still have to remember to take the list with you!