Try it with 500 g flour
At 65% water, 2% salt and 0.6% yeast, 500 g flour gives 325 g water, 10 g salt and 3 g yeast. The 838 g of dough makes two 419 g pieces before baking.
Why the percentages can add up to more than 100%
Flour alone is 100%. Multiply its weight by each percentage divided by 100. To work backwards, multiply your target dough weight by 100, then divide by the sum of the four percentage numbers. In the example above that sum is 100 + 65 + 2 + 0.6 = 167.6. The total is before baking; it is not the weight of the finished loaf.
This worksheet includes only flour, water, salt and yeast. The starting percentages illustrate the arithmetic; use the amounts and yeast type in your recipe. For dough with a preferment, oil or other ingredients, account for those separately.