To find the portion of adults that consume the recommended daily amount of calcium, you can express the number of adults consuming the recommended amount in a fraction or decimal form based on the given percentage.
77 out of every 100 adults means that the fraction of adults consuming the recommended amount is:
\[ \frac{77}{100} \]
To express this as a decimal, you can simply divide 77 by 100:
\[ \frac{77}{100} = 0.77 \]
So, the portion of adults that consume the recommended daily amount of calcium is 0.77 or 77%.