13. (15 points) As shown in the figure, Figure (1) is made up of 1 small cube with an edge length of 1, Figure (2) is made up of 5 small cubes with an edge length of 1, and Figure (3) is made up of 14 small cubes with an edge length of 1. Following this pattern, find:
(1) How many small cubes with an edge length of 1 are used to form Figure (6)?
(2) The surface area of the solid in Figure (10).


【Answer】Solution: (1) According to the observation, there are $1^{2}$ small cubes in Figure (1); $1+2^{2}$ small cubes in Figure (2); $1+2^{2}+3^{2}$ small cubes in Figure (3); $1+2^{2}+3^{2}+4^{2}$ small cubes in Figure (4);

$1+2^{2}+3^{2}+4^{2}+5^{2}$ small cubes in Figure (5); $1+2^{2}+3^{2}+4^{2}+5^{2}+6^{2}=91$ small cubes in Figure (6), so the answer is: 91.
(2) The surface area of the stack includes: 2 front and back faces, 2 left and right faces, and 2 top and bottom faces.