Please, firstly show your attempt. After that, ask what your problem is. Thanks for understanding.
Also, you can use these steps to solve:
1- take the numbers of popsicles and siblings as input from the user. (with using cin)
2- calculate the remaining of popsicles to siblings. (with using %)
3- use a condition for making a decision like give away. (with using if-else) and print your choice (with using cout)
I hope, it helps. Happy coding!