Teaspoon
There is more than one type of teaspoon:
A US teaspoon is 4.93ml: US teaspoon
A UK teaspoon is 5ml: UK teaspoon
UK gallons
A UK gallon is a unit of volume used in the United Kingdom for measuring liquids such as fuel and water. One UK gallon is about to 4.54609 liters or 0.16054 cubic feet making it substantially larger than the US gallon.