Unit rate in this case is the cost for 1 ounce of chocolate chips.
If 6 ounces costs $2.49, then just divide the cost of 6 by 6 to get the unit rate.
2.49 / 6 = 0.415
1 ounce of chocolate chips costs $0.415.
You can also solve this by setting up an equation.
6 ounces = $2.49
6x = 2.49
Isolate x by dividing both sides by 6.
6x / 6 = x
2.49 / 6 = 0.415
x = 0.415
1 ounce of chocolate chips costs $0.415.
So the unit rate is 1 ounce costs $0.415.