1. **State the problem:** Simplify the expression $6 \times 21 - 12 - 7 + 24 \div 3 + 33 + 12$. 2. **Recall the order of operations:** Use PEMDAS (Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right)). 3. **Calculate multiplication and division first:** $$6 \times 21 = 126$$ $$24 \div 3 = 8$$ 4. **Substitute these values back into the expression:** $$126 - 12 - 7 + 8 + 33 + 12$$ 5. **Perform addition and subtraction from left to right:** $$126 - 12 = 114$$ $$114 - 7 = 107$$ $$107 + 8 = 115$$ $$115 + 33 = 148$$ $$148 + 12 = 160$$ 6. **Final answer:** $$160$$