15) \( (6-4) \times 49 \div 7 \)

To solve \( (6-4) \times 49 \div 7 \), we start with the parentheses. \( 6-4 = 2 \). Now the expression is \( 2 \times 49 \div 7 \). Next, we perform the multiplication: \( 2 \times 49 = 98 \). Finally, we divide: \( 98 \div 7 = 14 \). So, the final answer is \( 14 \). Here's a fun fact: The order of operations, or PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction), helps us keep our calculations organized! Remember, without following this order, results can be wildly different! If you want to challenge yourself, you can try a similar expression with larger numbers, such as \( (150-75) \times 300 \div 25 \). This will not only strengthen your skills but also help you to get comfortable with various operations and their sequences!