What your daughter is doing is decomposing numbers. It shows great understanding of number and flexibility in her thinking. If you think about it, she's already figured out how "carrying" works--and why! It's sort of like emptying a coin jar and totaling up the contents--we usually don't count coin by coin or grab random amounts to add together, we group them into "easy sets" for counting. To use your example, imagine that your daughter slid nine dimes across the table, then slid over another five--she's recognizing that one of those dimes will complete her "first set" and leave her with an extra four.
