To ask you to help me with my maths equation for pizza

[Munrow]

I'm trying to use up a hole cube of fresh yeast which comes in at 42grams per pack

The recipe I'm following requires 25 grams of fresh yeast per batch.

One batch contains 500grams of flour.

I would like to use up the 42grams of yeast. So how much more flour do in need if I used the whole 42grams of yeast?

Each gram of year requires 20g of flour (I think) so 840g of flour?

*yeast

how much more flour do in need if I used the whole 42grams of yeast
You need 340g more, or 840g in total.
42/25 = 1.68
1.68 * 500 = 840g

Yes - 840g in total.

500/25 = 20 (g) which is how much flour per gram of yeast

20 x 42 = 840g in total

I worked it out that 1 gram of yeast requires 20g of flour so 42gx20g = 840g

You've got 17g left. So this is enough to raise 17/25 times 500g flour = 380g.

But the yeast/ flour ratio is not an exact science. You need enough yeast to raise the amount of dough, but a little less will work but might take longer to rise, and a bit extra will basically go to waste - you'll still get your 500g pizza dough. So your question is better phrased as "how much more dough can I make" rather than "how much more flour do I need"

340g not 380g. Should check sums I do in my head.