1. a) 1 5/8 + 4/4

1. Convert mixed number to improper fraction: 1 5/8 = 13/8.
2. Find a common denominator for 8 and 4, which is 8. Convert 4/4 to 8/8.
3. Add the fractions: 13/8 + 8/8 = 21/8.
4. Convert back to a mixed number: 21/8 = 2 5/8.