Concentration vs Total Quantity

For a demonstration of concentration versus total quantity: get three 100 mL graduated cylinders. And put a bit of food colouring in one and maybe dilute to 10 mL. Put an equivalent amount of food colouring in another and make it up to 30 and 100 mLs. It’s the same amount of food colouring in 10 mL, 30 mL, 100 mL. What will they look like? Dark, medium and lighter. Look down the top, what will they look like? Identical. It’s the same amount of molecules absorbing, blue, or whatever colour’s being absorbed. When you look sideways the concentration is shown but when you look downwards the total amount is shown.