Why use a scale? I think you are doing it the hard way.

The rule of thumb for bleach is: 1 gallon of 6% adds exactly 6ppm to 10,000 gallons of water.

Since you have 5,000 gallons, you would need only 2 quarts of 6% to get a rise of 6%. 3/4 of that (a quart and a pint) would raise your FC by 4.5ppm.

Did you add 3 pints of 6% bleach?

BTW, if the bleach is 5.25%, substitute 5.25 for 6. If it's liquid chlorine and it's 12.5%, substitute 12.5 for 6.

You don't even need a calculator!

this is based on the formula for bleach addition:
FC added = (1,000,000/pool gallons) * 0.06 * # gallons of bleach, where 0.06 is 6% bleach. Use .125 for 12.5% LC.