One billion is equal to 1,000 million. One billion is written with a one followed by nine zeros, while one million is written with a one followed by six zeros. One billion is also written as 10^9, and one million is written as 10^6.
Ten ones make 10, 10 10s make 100 and 10 100s make 1,000. One million contains 1,000 1,000s. One trillion is 1,000 billions or one million millions. It is written as a one followed by 12 zeros or 10^12. In Great Britain, however, one billion is written with 12 zeros and one trillion with 18 zeros.