When I introduce addition (even as early as the first few days of school when we do the "houses" for each number, I have my munchkins use these workmats. It's a great visual and gives them the math talk that they need to be familiar with. I've used the divided plates, but have found more success with this little workmat. I give each student one workmat, in a sheet protector, to be stored in their desks to use when they need them. These are great for those kiddos that still need a visual representation of a number sentence in January because they can pull them out of their desks as needed and can be used for addition and subtraction. :)
Image is linked. Please say thank you if you take this.