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? Let's be accurate as possible.
Marcus had 18 / 2 = 9 pebbles left. After Freddy gave him more, he has 9 + 30 = 39 pebbles.
The answer: 39.