Word Request – Swapping First Parts of Two Words

The important information in this thread is from Etymonline.com. They get their information from the famous English linguist Otto Jespersen:, who said this

The reason for writing I is ... the orthographic habit in the middle ages of using a 'long i' (that is, j or I) whenever the letter was isolated or formed the last letter of a group; the numeral 'one' was written j or I (and three iij, etc.), just as much as the pronoun.

[Otto Jespersen, "Growth and Structure of the English Language," p.233]

This means:

In the Middle Ages sometimes people needed to write 'i' a lot. For example, they used Roman numerals. Roman numerals are Roman symbols for numbers. They looked like this:

1. i
2. ii
3. iii
4. iv
5. v
6. vi
7. vii
8. viii
9. ix

You can see that they used a lot of 'i's in their numbers. Because it's difficult to read these numbers when they are mixed up with writing, they used to make the last 'i' in any number very big. It used to look like capital 'i': "I" - or it used to look like 'j': "J".

So for example, in the middle ages, people used to write the number three like this:

• iiI

... or like this:

• iiJ

Because of this when there was only one 'i' it used to look like this:

• I

... or like this:

• J

So when we started to use the letter 'i' to represent the pronoun I, people started to print it like one 'i'. They printed it like this:

• I

i hope this is helpful!

You can call the digits to the left of the decimal point integer digits or integral digits and those to the right of the decimal point fraction digits or fractional digits.

Java I/O, Harold (2006):

For instance, in the number 31.415, there are two integer digits and three fraction digits.

Microprocessor Engineering, Holdsworth (2013):

...where n is the number of integral digits and m the number of fractional digits.

Perhaps these terms are not well-established, but they are used in the literature and will be understood in the appropriate context.