Have several sets of 5 interlocking cubes, legos, or blocks with 2 different colors.  Talk about how you are holding 5 objects, but you can take them apart by color as you count the amounts in each section.  For example, 1 red block and 4 yellow blocks.  When they have all been taken apart, you can put them back together.  Help your child(ren) discover how two different colored objects can be put together to make 5.  

Have items ready to complete and extend patterns.  You can use blocks, poker chips, candy, cards created for holidays, etc.  Hand the materials to your child(ren) and ask them to sort them by likeness.  Ask them to create, duplicate, complete, and/or extend a pattern.  For example, you can hand them a handful of colored goldfish crackers or colored cereal rings.  Once they are sorted, count how many you have of each color. Ask them to select at least 2 colors to make patterns with. Allow them to create more complex patterns as they are ready.