d. \( 7 \times 0.3= \)

To solve \( 7 \times 0.3 \), think of it as multiplying 7 by 3 and then moving the decimal point. \( 7 \times 3 = 21 \), and since you're multiplying by 0.3 (which is the same as \(\frac{3}{10}\)), you shift the decimal one place to the left, giving you \( 2.1 \). So, \( 7 \times 0.3 = 2.1 \). Multiplying decimals often trips people up because of the decimal placement! A common mistake is forgetting to shift the decimal after doing the multiplication. Always remember to account for how many decimal places are in the number you're multiplying by; it makes all the difference in getting the correct answer!