Give the same paper to the second group and ask them to draw whatever they can without using the colours that were used by the first group. Time limit is 3 minutes. The third group has to draw in the same paper. They cannot use the colours used by the earlier groups. If the earlier group uses all the colours, the third group does not get to draw at all.
Time limit is one minute.
To understand the concept of equitable distribution of resources. Place some sweets in the center of the circles. Ask each child to pick a sweet not more than one at a time. Gradually add more sweets only to the inner circle. Now, tell those who have less sweets to grab from others who have more than their share.