There are 8 Ounces in a cup. Therefore the Tablespoon is 1/2 Ounce. A teaspoon is 1/3 of a tablespoon or 1/6 of an ounce. Remember this, 128 ounces in a gallon. 1/2 of a gallon is the next stop down = 64. 1/2 of that is a quart = 32 ounces. 1/2 of that is a pint = 16 ounces.
The difference between US Letter and Legal Paper sizes and international A4 is discussed here, however it is important to say that Letter is effectively the equivalent to A4 size in the USA.
Computer Science. For US versions of Microsoft Word, the default paper size is 8.5 X 11 inch letter. While you will probably print most of your letters, reports, and other documents on this size paper, at some point in time you will probably want to use a different size paper like legal size or some other more obscure paper.