=2116×6,

=12696 (square centimeter).

Answer: They need at least 12696 square centimeters of red paper.

3. Solution: (1× 12+6× 12 )×

Answer: The area of this trademark paper should be at least 384 square centimeters.

4. Solution: Painting area: 8×6+(8×3+6×3)×2-11.4,

=48+84-11.4,

=12.6 (square meter.

the amount of money spent: 12.6×6=723.6 yuan;

A: It costs 723.6 yuan to paint this classroom.