Multiplication till 400

Calculate:

The number of examples:
Numerical difficulty:
Range of values:
Multiplicity:

20	×	16	=
5	×	4	=
7	×	10	=
18	×	18	=
6	×	13	=
13	×	13	=
15	×	21	=
19	×	18	=
12	×	18	=
16	×	18	=