Solution: let's assume that meat is y yuan/Jin with x angle, then,

x+4 = y①； x- 1.6= 1/2y②

Solve, get: x=y-4③, substitute ②, get:

y-4- 1.6=0.5y

0.5y=5.6

y= 1 1.2

When y= 1 1.2, x= 1 1.2-4=7.2.

So, he brought an angle of 7.2.

You can also think of it this way: half a catty, in order to pay,

* * * 4+ 1.6 = 5.6, the price difference is half a catty.

Then the angle of * * * is 5.6+ 1.6=7.2.