Here we shall use the unitary method.
We shall first find the cost of 1 kg oranges and then find the cost of 8 kg ornages.
The fraction 1/2 = 0.5
Also 100 cents = $1
So 25 cents = 25/100 = $0.25
The cost of 0.5kg oranges = $0.25
Hence the cost of 1 kg oranges = 2 ×0.5kg shall be
= 2 ×0.25
= $0.50
So the cost of 8 kg oranges
= 8 × 0.50
= $4.00
The cost of 8 kg oranges at 25 cents for half kg shall be $4.00