1. We are asked to evaluate the expression $840 - 10^2 \times 6$. 2. According to the order of operations (PEMDAS/BODMAS), we first calculate exponents, then multiplication and division from left to right, and finally addition and subtraction. 3. Calculate the exponent: $$10^2 = 100$$ 4. Multiply: $$100 \times 6 = 600$$ 5. Subtract: $$840 - 600 = 240$$ 6. Therefore, the value of the expression is $240$.