How much yeast is in one loaf?

From Fleischmann's website:

How do I use Fresh Active Yeast?

Fresh Active Yeast is the product that Fleischmann's has been manufacturing for over 130 years. It is also traditionally known as compressed or cake yeast. It has not undergone the drying process, so it does not need to be dissolved before use: soften the cake in warm water first OR simply crumble the yeast into dry ingredients (if directed by recipe). Fresh yeast requires two rises. Yeast is available in two different sizes: 0.6 ounces and 2 ounce household cakes

How do I substitute dry yeast for Fresh Active Yeast?

One .6 ounce cake is equivalent to 1 envelope of dry yeast. One 2-ounce cake is equivalent to three envelopes of dry yeast. Follow the directions on the package recommended for the type of yeast you substitute.

How much dry yeast is in 1/4 ounce envelope?

About 2 1/4 teaspoons.