Make 5 animated videos explaining mental math concepts

I want to make animated videos to explain mental math concepts. There will be only one concept per video. The video won't be longer than 1 minute. I want to make at least 5 such videos. I don't care which software you use. The video is for kids, so it has to be playful and colorful. I will provide the content for the video, you will have to design it, add music to it, and develop the video. There has to be playback also to the video but I don't need you to record the audio, just use the standard text to speech option in your video. Serious bids only. Bid what you will charge for 5 videos and how long it will take you to develop the video. * Do not bid unless you are serious about fulfilling this project. * Your bid is fixed once it is placed. You will not be able to negotiate a new price.