How to make animations like these ? I have tried with drawing on whiteboard and taking time lapse of it. However from videos, they looked like picture is drawn first and then erased by some software. Any idea/tips to make such animations ?
They are fake.
Although they can be done in a real stop motion, or simply filming you drawing and then speeding up on post pro, there are tools to just grabbing a black and white image and apply the effect. Take a look at this: https://goanimate.com/
Other option is using an animation software. But animating the hand will be a pain.