What is the sum of 6 feet 10 inches and 8 feet 9 inches

 The answer is 15 foot 7 inches or 187 inches.

15 ft 7 inches

Here are the steps to doing this,

1. Write out

    6 ft 10 inches
+  8 ft 9 inches


2. Add the inches first, 10 + 9 = 19
3. Next, add the feet, 

6 + 8 = 14

What you have is 14 feet 19 inches
Hopefully, you know that 12 inches is equivalent to one foot.

4. Subtract 12 from 19, and you get 7.
5. Your answer is 15 feet 7 inches

Hope this helps!

2,4,5,8,10 are divisible by 40