Need to know how to read the roof pitch on my square

2,925 sq. ft. If it is not a lean to roof then we would have to know the pitch of the roof and number of dormers, etc...

If you have access to your attic measure out 12" from edge, then measure straight up from there to roof and that will give you the pitch.

Using a rafter square determine the pitch of the roof.

Assuming you mean a pitched roof
you need a roof mount kit from you local AC supplier
they are a generc item

The numbers on the side of a framing square are used for many things. The small leg allows you to quickly lay out a wall on16" centers. The other rows of numbers help you figure the correct sizes to cut for hip roofs (roofs that have slope on all four sides.)You can get an instruction Manual from Stanley or it may be availabile on the net. Google (framing square instructions)

Ash fault? I think you mean "asphalt" but that's OK. You haven't given enough information to solve the problem, but here's what you need to do.

You know the area of the roof is 300 square feet (sq ft). You should know the area of each asphalt shingle, although that's the information you didn't give. When you know that figure, the calculation is very simple:

number of shingles needed = area of roof / area of one shingle

I don't know if this is a class problem, or if you really have a roofing job. Don't forget that on a real roof, the shingles overlap. If you do the calculation, the number you get is right only if you lay the shingles edge-to-edge. A real-world roof would need probably twice that number. Shingles come packed in bundles, and they usually tell you the area they cover. (By the way, 100 square feet is termed a "square".)

Assuming you already know the angle you require, take the edge with the level on it(if you have that model) or the side that hangs over and hook it on the edge of the board. If you look at the top, on the 90 degree end, it says "pivot", and that is where you will spin the square around. You read on the 45 degree end that was hooked to the board for you angle. If you are trying to cut a rafter at a specific pitch such as a 6/12 you will spin the square around until the 6 on the Common scale lines up with the edge of the board. The Hip/Val scale is for cutting hips and valleys for the roof structure.
If you have any other questions, feel free to contact me here

Bob

have you looked om ebay

take your board make a mark on the side of board put your speed square on that mark(the squared side)flat up agianst the board rotate the square until the 15 deg comes to the other side of board then make your line.