Learning Resources Minute Math Electronic Flash Card, Ages 6+

Amazon.com Price:  $11.99 (as of 31/12/2019 08:44 PST- Details)

Encourages practice of operations (add/subtract or multiply/divide) and early algebraic skills related to equations and the commutative property
Offers a 60-second timed mode and a low-pressure untimed mode, plus 3 levels of difficulty
Reinforces arts of the equation through color-coded screen frames