Think of the tens and the units separately:
16 x 34
= (10 + 6)(30 + 4)
Then we can distribute and get:
10(30 + 4) + 6(30 + 4)
And then further to get:
(10 x 30) + (10 x 4) + (6 x 30) + (6 x 4)
Each of these multiplications is easy enough to do in your head:
300 + 40 + 180 + 24
Add up the results:
300
180
