Solve the following multiplication and addition problems, including a word problem about fan blades.

The boxes represent multiplication tables.

Row 1 (2 times table):

Row 2 (5 times table):

Row 3 (10 times table):

• $3 + 3 + 3 + 3 = 4 \times 3$
• $5 + 5 + 5 = 3 \times 5$

• $3 \times 4 = 3 + 3 + 3 + 3$
• $4 \times 6 = 4 + 4 + 4 + 4 + 4 + 4$
• $1 \times 7 = 1 + 1 + 1 + 1 + 1 + 1 + 1$
• $4 \times 5 = 4 + 4 + 4 + 4 + 4$

• $4 \times 2 = \boxed{8}$
• $3 \times 8 = \boxed{24}$
• $4 \times 7 = \boxed{28}$
• $2 \times 9 = \boxed{18}$
• $2 \times 7 = \boxed{14}$
• $5 \times 6 = \boxed{30}$

• $2 + 2 + 2 + 2 + 2 = 5 \times 2 = \boxed{10}$
• $4 + 4 + 4 + 4 + 4 + 4 = 6 \times 4 = \boxed{24}$
• $3 + 3 + 3 + 3 = 4 \times 3 = \boxed{12}$
• $5 + 5 + 5 = 3 \times 5 = \boxed{15}$

A fan has three blades. A room has four fans.
To find the total number of fan-blades, multiply the number of blades per fan by the number of fans.