1 pound equals 16 ounces.
Convert the weight from pounds to ounces.
2 pounds 3 ounces:
2 pounds x 16 ounces per pound = 32 ounces
32 + 3 = 35 total ounces
Now find the difference by subtracting:
56 ounces - 35 ounces = 21 ounces
The kitten gained 21 ounces ( 1 pound 5 ounces)