My question is simple What is 19.53 to the nerest liter?

The question is not so simple. In fact, it's quite ambiguous, because

we don't know what unit the " 19.53 " is.

- - If it's 19.53 milliliters, then the nearest liter is zero liters.

- - If it's 19.53 pints, then the nearest liter is 9 liters.

- - If it's 19.53 liters, then the nearest whole liter is 20 liters.

If it's 19.53 milliliters, then the nearest liter is zero liters.

If it's 19.53 pints, then the nearest liter is 9 liters.

If it's 19.53 liters, then the nearest whole liter is 20 liters.

If it's 19.53 quarts, then the nearest whole liter is 18 liters.