Learning Numbers and Math Facts in Spanish

My boys can count to 20 in Spanish, but I can tell it is more by rote memorization because they have difficulty naming individual numbers. When they were learning skip counting in English we listened to a LeapFrog song that I downloaded from Amazon.com. It really helped them to have the song's rhythm in their heads as they completed their math assignments. Now that I would like to teach them to be more fluent in Spanish, I am looking for Spanish songs similar to the ones by LeapFrog.

I found several available for free on YouTube (search for Boca Beth) as well as for purchase as MP3s on various websites. However, the sound quality seemed pretty poor which would be confusing for children who are still working on correct pronunciation.

Here are some products that I have found:
1) Spanish Random Number CD from Creative Mathematics-- A great idea, but it is $10 plus shipping for something I already do for free at home. I'll consider getting it in a couple of months if my home efforts don't pan out.
2) Sara Jordan Bilingual Songs-- these are available from the publisher's website along with lyrics or as MP3 downloads from Amazon.com. We have enjoyed Sara Jordan's bilingual songs about food, weather, etc. on Volume 1. Their songs about numbers are spread across several albums so I chose to purchase individual songs for $.99 each on Amazon. We now have Contando Hasta 30/ Counting to 30; Contando Por Decenas/ Counting by 10s; Formas y Tomaños/ Shapes and Sizes; and Contar regresivamente/ Count backwards, which is also about subtraction for numbers under 6.
3) Songs for Teaching-- MP3 albums and lyrics for songs on a variety of subjects. They don't have many Spanish math songs that go beyond basic counting, but I thought this one was a cute and easy to understand song about counting to 10's. I had to buy the entire $10 album but it had a few other songs that the kids will really like.

I have looked in to other resources for helping children learn Spanish and will post about them later on. It basically comes down to time commitment and working with a parent; but these songs and other resources are a great way to reinforce the lessons we are already doing at home!