The Deci-Point slide rule enables the location of the decimal points easily with the combination of the RN-DZ and √ scale below it. A couple of examples will suffice to demonstrate its use.
Calculating the square root of 365.
Using the front of the slide rule, we determine that the digits in the answer must be 191. We align the cursor with 365 on the D scale and since 365 has an odd number of digits we use the upper of the two square root scales provided.
Now using the reverse of the slide, we locate the number of digits, +3 on the RN-DZ scale and read the value of on the √ scale below to be +2.
This means that our answer must have two digits in front of the decimal point. Hence 19.1 is the result.
Calculating the square root of 0.000484.
In a similar fashion using the front of the slide rule, the digits in the answer must be 22. We align the cursor with 484 on the D scale and since 484 has an odd number of zeros we use the upper of the two square root scales provided.
Now using the reverse of the slide, we locate the number of zeros, -3 on the RN-DZ scale and read the value of on the √ scale below to be -1.
This means that our answer must have one zero behind the decimal point. Hence 0.022 is the result.
