- If node x is a non-full (< 2t-1 keys) leaf, then insert new key k in node x
- If node x is non-full but not a leaf, then recurse to appropriate child of x
- If node x is full (2t-1 keys), then ``split'' the node into
*x*_{1}and*x*_{2}, and

recurse to appropriate node*x*_{1}or*x*_{2}.