Alternatively, you could use the if formula. For example,

=if(C8="Wood",8,0) means If the value of C8 (input) is "Wood" then output the number 8. Otherwise, output 0.

To do multiple items, you would use simply add a comma. For example: =if(C8="Wood",8,0),if(c8="Some other Material",1,0),if(c8="Another thing",7,0)

You can also of course combine this with math. =B8*(=if(C8="Wood",8,0),if(c8="Some other Material",1,0),if(c8="Another thing",7,0))

Just be careful with your parentheses!

Alternatively, you could use the if formula. For example,

=if(C8="Wood",8,0) means If the value of C8 (input) is "Wood" then output the number 8. Otherwise, output 0.

To do multiple items, you would use simply add a comma. For example: =if(C8="Wood",8,0),if(c8="Some other Material",1,0),if(c8="Another thing",7,0)

You can also of course combine this with math. =B8*(=if(C8="Wood",8),if(c8="Some other Material",1),if(c8="Another thing",7,0))

Just be careful with your parentheses!