Question

$12:2^{2} +21:\sqrt{9} - 140:14$

Answer 1

$12 \div {2}^{2} + 21 \div \sqrt{9} - 140 \div 14 = \\ 12 \div 4 + 21 \div 3 - 140 \div 14 \\ 3 + 7 - 10 = 0$