Calculating yeast pitching amount

Northern Brewer General
1

I was able to get about a half liter of yeast from my local brewery. What would be the best way to calculate how much I should pitch from this half liter of yeast ?? I plan on brewing 5gallons of a pale ale with a OG of 1.052

2

You should Mr malty’s yeast calculator. And select yeast slurry.

Or just pitch the whole thing and ferment.