human
Marcus had 18 pebbles. He skipped half of them across the lake, but Freddy gave him another 30 pebbles. How many pebbles does Marcus have now?
assistant
How many pebbles did Marcus have left after skipping half of them? ** Marcus had 18/2 = <<18/2=9>>9 pebbles left.
How many pebbles does Marcus have now? ** After Freddy gave him more, he has 9 + 30 = <<9+30=39>>39 pebbles.
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