Explanation

In mathematical operation, involving addition the result would be correct up to minimum number of decimal places in any of the quantity involve. Given, L=2.3331 cm and B=2.10 cm. Taking correct up to decimal places and since, can be rounded off less than 5, the preceding digit is unaffiliated. $\therefore L = 2.33\ cm,\ B = 2.10\ cm$ $L + B = 2.33 + 2.10 = 4.43\ cm$