An adult elephant drinks about 225 litres of water each day. Is the number of days that an elephant’s water supply last for proportional to the number of litres the elephant drinks?
First step: draw an elephant. Second step: think about what’s happening. An elephant is drinking 225 litres of water per day. We want to know if the days that the water lasts is proportional to the amount of litres the elephant drinks.
This would be proportional. The water supply is decreasing by the same amount each day. That means that the remaining water supply is in direct relation to the days that the elephant has been drinking 225 litres of water.