The International Congress of Mathematicians (ICM) is the largest and most prestigious mathematical conference in the world. It is held every four years and attracts over 5,000 participants from all over the globe.

The Joint Mathematics Meetings (JMM) is the largest annual mathematics conference in the world. It is held in January and attracts over 20,000 participants from all over the globe.

The European Mathematical Society (EMS) Congress is held every four years and attracts over 5,000 participants from all over Europe.

The International Symposium on Symbolic and Algebraic Computation (ISSAC) is held annually and attracts over 1,000 participants from all over the world.

The International Symposium on Symbolic and Algebraic Computation (ISSAC) has the lowest attendance among the given conferences, with approximately 1,000 participants.

The International Congress of Mathematicians (ICM) has an attendance of over 5,000 participants, while the Joint Mathematics Meetings (JMM) has an attendance of over 20,000 participants. Therefore, the approximate ratio of attendance between the ICM and the JMM is 2:1.

The Joint Mathematics Meetings (JMM) has an attendance of over 20,000 participants, while the European Mathematical Society (EMS) Congress has an attendance of over 5,000 participants. Therefore, the difference in attendance between the JMM and the EMS Congress is 20,000 - 5,000 = 15,000.

Approximately 75% of attendees at the International Congress of Mathematicians (ICM) are from outside of the host country.

The Joint Mathematics Meetings (JMM) is held annually, while the International Congress of Mathematicians (ICM), the European Mathematical Society (EMS) Congress, and the International Symposium on Symbolic and Algebraic Computation (ISSAC) are held every four years.

Approximately 150 countries are represented at the International Congress of Mathematicians (ICM).

The International Congress of Mathematicians (ICM) is the oldest of the given conferences, dating back to 1897.

The Joint Mathematics Meetings (JMM) typically lasts for one week.

The International Congress of Mathematicians (ICM) is held in a different location each year, while the Joint Mathematics Meetings (JMM), the European Mathematical Society (EMS) Congress, and the International Symposium on Symbolic and Algebraic Computation (ISSAC) are held in the same location each year.

Approximately 300 sessions are held at the Joint Mathematics Meetings (JMM).

The International Symposium on Symbolic and Algebraic Computation (ISSAC) is primarily focused on symbolic and algebraic computation.