6
Half of 12 is 6
1 half added to 5 eights = 6
It is: 2.5+4.5 = 7
7(54)
Half of 6 is 3. Half of 8 is 4. 7 is not an even number, so half of 7 will not be a round number. Half of 7 is halfway between half of 6 and 8-halfway between 3 and 4. So half of 7 is 3.5 Additionally, you could multiply 7 by .5 to divide it in half. Your answer will be 3.5, for the reason explained above.
200g (7oz)
4.5 + 7.5 + 6 = 18
6
5' 7" + 6" = 6' 1"
one half is 6 twelfths and 7 twelfths is more than 6 twelfths
1/2 + 7/10 = 5/10 + 7/10 = 12/10 = 1.2