If a/b=c/d then
•a/d
•c/d
•b/c
•C/d

this is a really good and amazing rule as this makes the family to spend time together.

spending time with your children and parents is really really important in order to have a loving stable and affectionate family.

also the children can save their eyesight from being ruined and can use their time in studying or doing something productive for example playing some sport or playing an outdoor game like monkey in the middle.