Although AutoMathic allows certain classes of numbers to be writtenout as English words, numbers will usually be entered as a sequence of digits. There are a few restrictions when supplying literal numbers to AutoMathic:
Numbers may contain commas (,) as group separators  1,000,000 
Decimal fractions between 1 and 1 MUST have a leading zero  0.396 0.125 
Numbers may NOT be entered using scientific notation of any kind!  1x10^5 3.215e9 
Usually, numbers will be entered as a sequence of digits, but sometimes the context or style of input would make it more natural to use the written form of numbers. AutoMathic allows using words for simple numbers in the following categories:
Small integers and their plurals 

Small multiples of 10 and their plurals 

Common powers of 10 and their plurals 

Simple fractions and their plurals 

Inverse powers of 10 and their plurals 

Special numbers and their plurals 

Mathematical Constants  Golden Ratio, e, Pi, Avogadro's number 
Written numbers can always be combined as long as the combination is purely multiplicative, not additive. For example:
three hundred  3 x 100 
forty billion  40 x 1,000,000,000 
five sixteenths  5 x 1/16 
two dozen  2 x 12 
six gross  6 x 144 
half a million  1/2 x 1,000,000 
Note that, contrary to standard writing conventions, AutoMathic's combined numbers must NOT be hyphenated (e.g. "twothirds")... Hyphens would be misinterpreted as subtraction!
Additive combinations are only safe to use when they are not part of a larger term:
three and a half  3 + 1/2 
two and five sixteenths  2 + 5/16 
Complicated written numbers (that imply multiplication and addition) are usually NOT understood by AutoMathic! Here are ways of writing out 256 that get misinterpreted:
Input  Interpretation 
two hundred fifty six  2 x 100 x 50 x 6 = 60000 
two hundred and fifty six  2 x 100 + 50 x 6 = 500 
The only way to use an additive combination as part of a larger term is to enclose the combination within parentheses to help guide the translation and remove the ambiguity:
Input  Interpretation 
three and a half thousand  3 + 1/2 * 1000 = 503 
(three and a half) thousand  (3 + 1/2) * 1000 = 3500 
Using parentheses works, but it is so unnatural and exacting that it defeats the purpose of using written numbers in the first place! It is most effective to use written numbers for the simple cases and multiplicative combinations only.