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.
A3 paper, which is functionally equivalent to tabloid size paper (11 x 17 paper), is appropriate for bi-fold brochures and other full-size presentation or advertising documents. A4 paper, functionally equivalent to letter size paper (8.5 x 11), is the appropriate paper size for correspondence, records, and invoices.