Foam letters and numbers like these designed to be played with in a bath tub, can be used for so much more than bath time. This is how my son learned to read fluently by the time he was 3 years old. Of course, the results are different for everyone. Not every child will read at age 3. But, these letters helped. Here's how I used them:
I would sit down to nurse my newborn daughter when my son was 21 months old. I would bring with me a tub of foam bath letters. As I sat and nurse her which took approximately 20 minutes or less every 4 hours, I would pull out a foam letter. I would hand it to him and let him investigate it any way he liked. I would then say things like, this is an M. An M says, "MMMMMM!" The same way I did with pictures of cows, pigs or cats when I would say, "This is a cow, the cow says moo!" Or, "This is a pig. the pig says, "Oink." Or, "This is a Cat. The Cat says 'Meow!'" You get the idea! I presented the letters to him in the same manner I would present pictures of animals or other pictures of word-related items.
The result is that he would pick up a letter and tell me it's name and it's sound. He eventually (and, it didn't take long) put the sounds together himself.
This concept is an excellent way to provide a solid start to reading for your child!