The two sentences have slightly different meanings:
1. "The boys are on the ice with their skates."
* This describes the boys being physically on the ice and wearing their skates, but it doesn't necessarily mean they are skating. They could just be standing, sitting, or preparing to skate.
2. "The boys are skating on the ice."
* This explicitly states that the boys are actively skating on the ice, meaning they are moving around using their skates.
Key Difference:
* The first sentence focuses on their location (on the ice) and their equipment (skates), but not their activity.
* The second sentence highlights the action they are doing (skating).