\( 68 \div 2 = 34 \text{ ост. } 0 \)
\( 34 \div 2 = 17 \text{ ост. } 0 \)
\( 17 \div 2 = 8 \text{ ост. } 1 \)
\( 8 \div 2 = 4 \text{ ост. } 0 \)
\( 4 \div 2 = 2 \text{ ост. } 0 \)
\( 2 \div 2 = 1 \text{ ост. } 0 \)
\( 1 \div 2 = 0 \text{ ост. } 1 \)
\( 68_{10} = 1000100_2 \)
\( 197 \div 2 = 98 \text{ ост. } 1 \)
\( 98 \div 2 = 49 \text{ ост. } 0 \)
\( 49 \div 2 = 24 \text{ ост. } 1 \)
\( 24 \div 2 = 12 \text{ ост. } 0 \)
\( 12 \div 2 = 6 \text{ ост. } 0 \)
\( 6 \div 2 = 3 \text{ ост. } 0 \)
\( 3 \div 2 = 1 \text{ ост. } 1 \)
\( 1 \div 2 = 0 \text{ ост. } 1 \)
\( 197_{10} = 11000101_2 \)
\( 1581 \div 2 = 790 \text{ ост. } 1 \)
\( 790 \div 2 = 395 \text{ ост. } 0 \)
\( 395 \div 2 = 197 \text{ ост. } 1 \)
\( 197 \div 2 = 98 \text{ ост. } 1 \)
\( 98 \div 2 = 49 \text{ ост. } 0 \)
\( 49 \div 2 = 24 \text{ ост. } 1 \)
\( 24 \div 2 = 12 \text{ ост. } 0 \)
\( 12 \div 2 = 6 \text{ ост. } 0 \)
\( 6 \div 2 = 3 \text{ ост. } 0 \)
\( 3 \div 2 = 1 \text{ ост. } 1 \)
\( 1 \div 2 = 0 \text{ ост. } 1 \)
\( 1581_{10} = 11000101101_2 \)
Ответ: 6810 = 10001002; 19710 = 110001012; 158110 = 110001011012.