Final answer:
To find the change you will receive when buying an orange, subtract the cost of the orange from the amount given.
Step-by-step explanation:
To find the amount of change you will receive when you buy an orange for 50 kobo and give 100 kobo, you need to subtract the cost of the orange from the amount you gave. In this case, the cost of the orange is 50 kobo, and you gave 100 kobo. So, the change you will receive is 100 kobo - 50 kobo = 50 kobo.