The dual number does not exist in English grammar.

I learned about Avogadro's number in chemistry class.

We need to calculate the aggregation number of this compound.

Number theory is a branch of mathematics that primarily studies the properties of integers.

Numerology is the study of deciphering the secret meanings of numbers.

She is interested in numerology and wants to know her destiny.

A negative number refers to a number less than zero.

A positive number is a number greater than zero.

Please adjust the frequency of this radio.

After the earthquake, the number of dead increased rapidly.