3 ms·
The trick can make any square easier. Take 27 * 27, make it 3 up and 3 down, i.e. 30 * 24 = 720. Then adding the 3 squared you get the answer 729.
by jonsen 6y ago
The trick can make any square easier. Take 27 * 27, make it 3 up and 3 down, i.e. 30 * 24 = 720. Then adding the 3 squared you get the answer 729.