I need professional explainer video animation

Information for the business: Educational videos
Industry: Education
Design details: We are looking for an explainer video animation designer to develop interactive educational videos for our users (120 explainer videos). The videos are worked examples of core subjects for primary school.
Our target audience are children in years 1 to 6.

The video must include the following:

 Up to 350 words (scripts will be provided)
 High definition and voice over (both male and female)
 Royalty free background music relevant to the users
 Colourful, engaging and re-usable background images and animation

As this is a high-volume work, We are looking for sellers who can demonstrate that they've delivered similar portfolios. This may be a job for an organisation instead of an individual – no timewasters please.

When responding, please provide the quote for developing 120 videos. We may ask you to produce a paid sample video before finalising the contract.
Target audience: Children
Ideas for the visual style: Fun and interactive videos
Extra notes: