1. The problem is to simplify the expression $100 - 100 \div 10 - 10$. 2. According to the order of operations (PEMDAS/BODMAS), division is performed before subtraction. 3. First, calculate the division part: $100 \div 10 = 10$. 4. Substitute back into the expression: $100 - 10 - 10$. 5. Perform the subtraction from left to right: $100 - 10 = 90$. 6. Then, $90 - 10 = 80$. 7. Therefore, the simplified value of the expression is $80$.