What is pi? (1000 iterations.) <-- This is accurate to 3 significant figures
What is pi? (10000 iterations.) <-- This is accurate to 4 significant figures
What is pi? (100000 iterations.) <-- This is accurate to 5 significant figures
What is pi? (1000000 iterations.) <-- This is accurate to 6 significant figures

What is e? (10 iterations) <-- This is accurate to 6 significant figures
What is e? (20 iterations) <-- This is accurate to 16 significant figures
What is e? (50 iterations) <-- This is accurate to greater than 16 significant figures
What is e? (100 iterations) <-- This is accurate to greater than 16 significant figures