Gifted, bright, smart, talented are different things. You can have a talented failure or a gifted student who makes Cs or a bright child who's a little loosey-goosey but works hard and gets the As that the smart kid won't earn.
Are you using math stations or math centers in your classroom? If not, Laura Candler's Math Stations ebook is your guide to getting started! If you're already using math centers, this book is a great resource for hands-on activities and math games.