(29 # _ )
/ \
/ \
/ \
(21 # _) (37 # 50 )
/ \ / | \
/ \ / | \
(7,9,11) (21,23) (29,30) (37,49) (50,100)
Insertion of 8,15,70 would not cause the root to split.The "8" will cause two splits, as described in the text of the lesson. It will only fill the root node, though, not cause it to split.
The "15" key would simply fill up the new second node from
the left.
The "70" key would simply fill up the rightmost leaf.
No root split required.