Company that have tons of different educational kits for children of different age and initial level. As an important addition, they have developed resources for teachers which are open access and allow to teach children at home:
vEx
Really good starting kit for children 6+ can be found here:
vEx GO Education Kits
Different resources for teachers can be found here:
vEx GO STEM Labs Teacher Portal
And carefully developed learning track can be found at the link below.
Pacing Guide
Another company with educational kits for robotics. Mainly targeted for elder children. Learning track must be purchased separately:
Tetrix