If you were asked to send a written rule to a really smart young person learning this for the first time, what would you write to them?
\(2+4=6\)
\(-3-5=-8\)
\(10+10=20\)
\(1+0=1\)
\(-7-7=-14\)
\(-4-9=-13\)
These are all correct. What's the pattern?
\(10-4=6\)
\(3-5=-2\)
\(10-10=0\)
\(3-9=-6\)
\(-4+15=11\)
\(4-15=-11\)