Num lock. The Num Lock key exists because earlier 84-key IBM PC keyboards did not have cursor control or arrows separate from the numeric keypad. Most earlier computer keyboards had separate number keys and cursor control keys; however, to reduce cost, IBM chose to combine the two in their early PC keyboards.
The most common rule. The most common and frequently used rule for writing numbers in APA style is determined by whether the number is under 10. All those numbers should be written out in word form, such as four or seven. A number 10 and above is written as a numeral, such as 10, 17, 233.
When writing for the Web: 1  Write numbers with digits, not letters (23, not twenty-three). 2  Use numerals even when the number is the first word in a sentence or bullet point. 3  Use numerals for big numbers up to one billon: 2,000,000 is better than two million.  Spell out numbers that don't represent specific facts.