As a potato chip is light weight I would use grams and milligrams.
There is only one metric system so I would use that.
You would use grams.
A meter stick would be one. A metric tape measure would be another.A measuring tape.a rulerA meter stickyou can use a metric tape or a yardstick or a metre trundle wheel and finally a metre stickA tape measure, calibrated in meters.A meterstickusually a metric measuring tape.
Liters
What metric unit would you use to measure a computer keyboard
The metric unit of the meter would be the appropriate measure of the area of classroom. Calculating area involves multiplying the length (in meters) of the classroom's length and width. Area of the classroom would be in square (^2) meters.
The basic metric unit for length is the metre. Rivers would be measure in kilometres (1,000s of metres)
Either grams or kilograms - depending on the size of the potato.
Normally pounds or Kilograms but larger amounts could move in to tons and metric tons
1 US gallon = 3.78541178 liters. Only if you mean pure water, then 1000 litres of water weighs 1 metric tonne. 1000 litres of water are 264.172052357 gallons that weigh 1 metric tonne.
Metres
The weight of a potato would best be measured in grams.
A microgram.
Potatoes are sold by the kilogram.
A thermometer.
distance
Centimeters
kilograms
you would measure it in kilograms