#### A Math Forum Project

Math Forum || Problems of the Week || Student Center

Use the digits in the year 1999 and the operations +, -, x, ÷, sqrt (square root), ^ (raise to a power), and ! (factorial), along with grouping symbols, to write expressions for the counting numbers 1 through 100.
1. All four digits must be used in the expression.
2. Only the digits 1, 9, 9, 9 may be used.
3. Double-digit numbers such as 19 or 99 may NOT be used.
4. The square function may NOT be used.
5. The integer function may NOT be used.
6. The digits may appear in any order in the expression. Older students with an understanding of integers should try to keep the numbers in the order 1, 9, 9, 9, but this is not mandatory.
7. This site is intended for the posting of answers generated by students.
8. Teachers may submit answers for their students.
9. Each answer should include the expression, the name of the student, the student's grade, and the name of the school.
10. Use the Web form once for each answer you would like to contribute. If you send more than one solution per form submission, we will be unable to include your answers on our solution page.