In this page, WTM will present some interesting activities similar to those that appear in another page (Digital Diversions). The difference, however, will be that here all ten digits — 0, 1, 2,…,9 — will be used. This is the reason the word “pandigital” is used in the title. (“pan” is a prefix that means [...]
A Digital Diversion Perform the following steps as indicated to see an interesting result. Form the smallest possible 4-place number using the four largest digits. Add that number to itself. The result is sum #1. Take sum #1 and add it to itself. The result is sum #2. Finally, take sum #2 and add it [...]
This article originally appeared in the January 1971 issue of the Journal of Recreational Mathematics. For additional coverage of this topic, go to Trigg Numbers In [1], C.W. Trigg discussed those positive integers less than 10,000, which are expressible in the form of N2 + M3, where N and M are also positive integers. Many [...]
Every good math student knows that pi is an irrational and transcendental real number and defined as the ratio of the circumference of a circle to its diameter. You can find all that information in any good math book. Now, WTM is going to introduce a new idea: pi words! Definition: a “pi word” (hereafter denoted [...]
On the page Distinct Digit Fraction Sums, we presented an activity wherein fractions formed by using various combinations of distinct digits had sums that were always 1. To refresh your memory, here is the introductory example again: 1 6 — + — = 1 4 8 On this page, we intend to expand on that [...]
Observe the following fraction addition carefully: 1 6 — + — = 1 4 8 On the left side of the equation there are four distinct digits — 1, 4, 6, and 8. While that may not look like earth-shattering news to some people, I think it looks nice. Can you make up a similar [...]
Egyptian method of multiplication on another page in this website, you might assume that here again we will select certain numbers from the second column to add, the result of which will be our desired product. That’s right, but which ones are they? The answer: the ones that are opposite odd numbers on the left!! 22 [...]
A Case Approach Everyone, or nearly everyone it seems, hates fractions, especially their addition and the other operations. Of particular note is the fact that the rules for addition and multiplication are often confused and interchanged, and the rule for division is just plain forgotten. This article attempts to present WTM’s own approach to one [...]
Here are four squares full of numbers. We will use them to perform a little math magic. Just follow the rules as given for each square. Choose any number in the square that you like. Draw a circle around it. Cross out all the other numbers that are in the same row as the number [...]
A New Twist to a Familiar Problem The concept is deceptively simple: fix one of the entries in the square so that it is “incorrect”. The object of the exercise then is to find the “culprit”; determine by how much it should be altered to bring things back into balance; and make the correction. Here [...]