It's alternating between + and -
first, third and fifth step are + (1, 3 and 5 respectively)
second, fourth and sixth step are - (2, 4 and 6 respectively)
So 4-6= -2!
It's alternating between + and -
first, third and fifth step are + (1, 3 and 5 respectively)
second, fourth and sixth step are - (2, 4 and 6 respectively)
So 4-6= -2!