Prime and Composite Numbers Worksheet with Answer Key

What's on the worksheet

1. Show each number is composite by writing a factor pair other than 1:
   3339497799
2. Write the number from its list of factors and say whether it is prime, composite or neither.
   1, 2, 4, 8, 161, 4111, 3, 91, 5, 7, 35
3. Can 89 lockers be put in a rectangle block of at least 2 rows and 2 lockers each?
4. Find which digits in the box make a two-digit number prime, and give a factor pair for the others.
5. Riddle: find every prime between 50 and 100 whose tens digit is 2 more than its ones digit.
6. Write 30 as the sum of two primes in every way, and say why 1 plus 29 does not count.