Ho do I improve my child's skills to match with other students?

How old is your child?

What skills? Language, Science, Math, Social, Writing?

All kids do not have equal skills... if anything its more like a bell curve and definitely NOT a straight line.

Here is an article that may interest you.

https://www.cdc.gov/ncbddd/childdevelopment/screening.html

If you can please give more information, we are here to help. If you are looking for ways to improve knowledge before Kindergarten, there have been major changes in education due to Common Core in the U.S. Please give details.

Giving your children extra tutoring in the field you would like to them to improve. You can do it either by yourself or going to someone else. And these days, you can find pretty a lot useful material online. So that will be a good way to to it:)