Select the proper placement for parentheses to speed up the addition for the expression \( 2+9+8+1 \). A) \( (8+2)+(9+1) \) B) \( (1+2)+(9+8) \) C) \( (9+2)+(8+1) \) D) \( (8+9)+(2+1) \)

To speed up the addition for the expression \( 2+9+8+1 \), you want to group the numbers that add up to a number close to 10, as this will make the addition easier. Let's evaluate each option: A) \( (8+2)+(9+1) \) - \( 8+2 = 10 \) - \( 9+1 = 10 \) - \( 10+10 = 20 \) B) \( (1+2)+(9+8) \) - \( 1+2 = 3 \) - \( 9+8 = 17 \) - \( 3+17 = 20 \) C) \( (9+2)+(8+1) \) - \( 9+2 = 11 \) - \( 8+1 = 9 \) - \( 11+9 = 20 \) D) \( (8+9)+(2+1) \) - \( 8+9 = 17 \) - \( 2+1 = 3 \) - \( 17+3 = 20 \) All the options result in the same sum of 20. However, option A is the most straightforward because it groups the numbers that add up to 10, which is the simplest addition. Therefore, the proper placement for parentheses to speed up the addition is: A) \( (8+2)+(9+1) \)