Part 1

Transcriber’s Notes:

Text enclosed by underscores is in italics (italics).

The whole number part of a mixed fraction is separated from the fractional part with -, for example, 2-1/2.

Additional Transcriber’s Notes are at the end.

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Multum in Parvo Library.

Vol. I. FEBRUARY, 1894. Published Monthly. No. 2.

How to Become a LIGHTNING CALCULATOR.

Smallest Magazine in the World. Subscription price, 50 cts. per year. Single copies, 5 cents each.

PUBLISHED BY A. B. COURTNEY, 671 Tremont Street, Boston.

Entered at Post-Office as second-class matter.

Instantaneous Addition.

Accuracy should be first considered, then rapidity. Quick adders, by the way, are the most accurate. Write the numbers in vertical lines, avoiding irregularity. This is important. Keep your thought on results not numbers themselves. Do not reckon 7 and 4 are 11 and 8 are 19, but say 7, 11, 19 and so on.

When the same number is repeated several times, multiply instead of adding.

When adding horizontally begin at the left.

3132 2453 12 | 6471 20 | 7312 15 | 2134 21 | ----- ---+ 21502

In adding long columns, prove the work, by adding each column separately in the opposite direction, before adding the next column. Many accountants put down both figures as in the illustration. The sum of the first column is 12; carrying one, the sum of the second is 20; carrying two, the sum of the third column is 15; carrying one, the sum of the fourth column is 21, and the total, 21502, is found by calling off the last two figures and the right-hand figures, following the wave line in the illustration. This method is better than the old one of penciling down the number to carry. If one desires to go back and add a certain column a second time, the number to carry is at hand and the former total is known.

How to Add Two Columns at Once.

2312 3253 2610 1256 3199 ----- 12630

To the inexperienced it will be a difficult task to add two columns at once, but many of those who have daily practice in addition find it about as easy to add two columns as one. Say 99 and 50 are 149, and 6 are 155, and 10 and 50 are 215 and 3 are 218, and 12 are 230. Carry 2, and say 33 and 12 are 45, and 20 are 65, and 6 are 71, and 30 are 101, and 2 are 103, and 23 are 126.

Much of the information here contained is compiled from W. D. Rowland’s valuable little volume, entitled “How to become expert with figures.” You can get this handy book by sending 25 cents in stamps to AMERICAN NATION CO., Boston.

Multiplication.

To Multiply Any Number by 11.

Write the first right-hand figure, add the first and second, the second and third, and so on; then write the left-hand figure. Carry when necessary.

219434 × 11 = 2413774

Put down the right-hand figure 4. Then say, 4 and 3 are 7; then, 3 and 4 are 7; then, 4 and 9 are 13, put down 3 and carry 1; then, 9 and 1 and 1 are 11, put down the 1 and carry 1; then, 1 and 2 and 1 are 4; then write the left-hand figure 2. In multiplying small numbers, such as 24 by 11, write the sum of the two figures between the two figures, making 264, the required product.

To Multiply by 101, 1001, etc.

To multiply by 101, add two ciphers to the multiplicand, and add to this the multiplicand.