# Courses > Number Sense

Q: What does Number Sense Class focus?

A: This class focus on below topics:

—- Mental math for speed calculation and accuracy

—- Shortcut for operation of integers and fraction

—- Basic Geometry Review

—- Solve Basic number theory problems quickly

—- Basic number counting and probability introduction

—- Number sense training

Q: Why should students take this class?

A: Students who enroll the class will have below benefits:

—- Increase calculation speed and accuracy

—- Boost conference in math contests (especially count down round)

—- Build strong foundation for number sense

—- Improve number sense score dramatically (Most students can improve 60~ 100 points in Math League NS round after 2-month class and practice)

Q: Who should take this class?

A: If your child fall below one or more of the categories below

— Students who currently participate Math League contest

— Students who plan to participate Math League contest in future

— Students who currently participate or plan on MATHCOUNT competition

— Students who wants to improve calculation speed

— Students who are interested in learning new methods

— Students who are bored with his/her regular school math

Q: Who can enroll NS 101 class?

A: It is the basic NS class and all students can take without previous training. However, they need to know operation of negative numbers; decimal; fraction and have basic concept of exponent, root, geometry shape; LCM/GCD to benefit from this class.

Q: Who can enroll NS 102 class?

A: It is the advanced class, so the prerequisite is NS 101. You need to get instructor approval to take NS 102 without previous enrollment of NS 101.

Q: Who can enroll NS 103 class?

A: It is same as NS 101. The class is for students who has not previous training, but currently or want to participate math league contests

Q: Who can enroll NS 104 class?

A: It is a refresh class for past students only. Students who took NS class last year (up to Advanced level) can enroll this special class

Q: If I miss the class, how can I make up?

A: All classes have videos and you can watch it after class. Video will expire by end of June 2021 (8 weeks after last class)

Q: Is there homework assignment?

A:  Yes. Students are expected to spend 1.5 to 2.5 each week to finish homework. Homework solution will be provided