Ledger lines are actually really easy. All a ledger line is, is a line that you add past the cleff lines for higher or lower notes. So an example would be if you need to play a high A you would just add a line as if there was a clef there. Usually you don't use more than 2 lines. I have seen razy amounts but for you we will only be going over 2 lines over and under for both clef.
First the treble clef ledger lines.
So the lowest note on the treble clef is a D. If you went lower you would get to C which would be the first leger line. Underneath that would be B. So you would put the note underneat the ledger line. Underneath that would be A and you would need to draw another line. Yes you need both lines drawn to understand that it is a line past C. Finally underneath that would be G which would be underneath the 2nd ledger line. Yes technically the 2nd ledger line and lower is actually the beginning of the bass clef nad if you do 1 ledger line between treble nad bass clef the clefs actually attach to each other nad becomae one big staff that work perfectly as you will see later.
First here is a picture of the notes and their ledger lines going under the treble clef. I will use whole notes so you can see them clearly:
Next we will go above the treble clef. The highest note on treble clef is a G, so to go one line about would be A. The next highest note would be B which would be on top of the 1st ledger line. Then we would add another ledger line which will be C. Finally we will put a note ontop of the 2nd ledger line which is D. Here is a picture showing this:
Ok so that same basic idea can be attached to the bass clef as well. So the highest note on the bass clef is B, so the first ledger line on the top would be C. Ontop of the first ledger line would be D. The 2nd ledger line would be E. And ontop of the 2nd ledger line would be F.
The lowest note on the bass clef is F, so the first ledger line on the bottom would be E. Below the first ledger line would be D, the 2nd ledger line down would be C and below the 2nd ledger line would be B.
Here is a picture showing both of those:
Now the last thing that is really cool is that when you add one ledger line between treble and bass clef it creates a super clef that works perfectly. But it isn't used, even though it should be!
Because that middle line is C since the bottom ledger line of treble is C and the top ledger line of bass is C, they meet up perfectly. This is also why it is called middle C becuase it is the C in the middle of the two clefs!
HOMEWORK: Be creative give me 3 other ledger line notes whether it be higher or lower on either clef!