Trying to understand math for Battery resistance ?

I=E2=80=99m working though understanding this description in this book. see=
 attachment link below.
I have tried this method for testing household batteries. I know there are =
other ways of testing batteries, but really I'm just trying to work my way =
through this book as a personal exercise.
Please refer to link below for the book example Im trying to follow. The ha=
nd written notes are mine based on what things the terms mean. Hopefully I =
have them right.
Can you tell me If I am performing the example properly.
Here is the math using the equations in the document, step by step broken d=
own based on the formula given in this book.
1. VL/RL =3D IL
2. VNL =E2=80=93 VL =3D NewVL
3. NewVL/IL =3D RI

My Tests

1.5 Volt Battery (Good Battery)
 I have an (A) Size 1.5 Volt battery, the following are my results.
VNL 1.569  No load.
VL 1.548     Load tested with R100 Resistor.=20
RL R100      Ohm Resistor

1. VL/RL=3D IL 1.548 / R100 =3D 0.1548 (IL)
2. VNL-VL=3D (NewVL) 1.569-1.548=3D 0.021 (NewVL)
3. VLNew/IL=3DRI 0.021/.1.548=3D0.1356589147286822 (RI)

The final result and internal resistance is 0.13 Ohms.
However when I go to the following web site
https://www.translatorscafe.com/unit-converter/en-US/calculator/batt-intern=
al-resistance/
And punch in the numbers I come to 1.357. Yes it=E2=80=99s the same number =
rounded up, but why is my number 0.13 and the web site moving the decimal p=
lace.1.3 Where am I wrong ?? They do seem to use a different math I think (=
This type of math is not my strong suit so Im not that clear on it.)
Who is right the web site my book or is my understanding / math wrong?

Here are the pages from the book that Im using. I hope they come through, I=
 don't post many pictures and things.=20
thank you very much.

[img]https://i.imgur.com/dyOeMjn.png[/img]

Here are the numbers I have entered into the www.translatorcafe.com web sit=
e calculator.
[img]https://i.imgur.com/NcVwyMk.jpg[/img]

On 2023-01-24, StevWolf <colinmarr0@gmail.com> wrote:

> 1. VL/RL= IL 1.548 / R100 = 0.1548 (IL)

1.548 / 100 = 0._0_1548

> 3. VLNew/IL=RI 0.021/.1.548=0.1356589147286822 (RI)

0.021 / 0.01548 = 1.357

> > 1. VL/RL= IL 1.548 / R100 = 0.1548 (IL)
> 1.548 / 100 = 0._0_1548 
> 
> > 3. VLNew/IL=RI 0.021/.1.548=0.1356589147286822 (RI) 
> 
> 0.021 / 0.01548 = 1.357

Human error, 
Thank you, Carless of me. 
Regards