Long division doesn't appear in most third grade math curriculum or Common Core Math Standards. Third grade math covers basic division with dividends up to 100.
Third graders learn the connection between multiplication and division. If they know that 3 times 8 equals 24, they know 24 divided by 3 equals 8. The focus is on learning basic multiplication and division facts. Students also learn the basic process of division with smaller numbers.
Long division problems appear in the fourth and fifth grade math standards. In fourth grade, students learn to divide four-digit numbers by one-digit numbers. In fifth grade, the curriculum includes problems with four-digit dividends and two-digit divisors.