One-to-one correspondence is an important basic math skill to teach your little ones. Understanding that the number spoken goes with the object being laid down or pointed to is necessary for any meaningful counting to occur.
There are many ways to practice this at home during play.
The easiest, most economical way, is to save an egg carton. I numbered ours because I wanted my daughter to associate a numeral for the number I was saying. We used rocks because we had a ton of them and they were free, but as with cards and counters, you can use anything for this - marbles, buttons, plastic animals....
A muffin tin would work nicely too.
Another one-to-one correspondence activity that was popular with Bear was to place the flat marbles on the dots of this number card. That the marble magnified the dot held her attention by providing a point of interest.
You can also use stickers instead of marbles. The stickers have the added benefit of developing the pincer grasp as the child pinches the sticker off the sheet and places it on the card. The stickers are on the number 4 in the photo. You can read about how we used it in more detail here and you can download the actual sheet (without dots) there too.