Mathwords logoMathwords

Nonillion — Definition, Formula & Examples

A nonillion is a very large number equal to 1 followed by 30 zeros. In the U.S. number naming system (short scale), it is written as 103010^{30}.

In the short scale system used in the United States and modern British English, a nonillion denotes the integer 103010^{30}, or equivalently, one thousand octillions. In the long scale system used in some European countries, a nonillion instead equals 105410^{54}.

Key Formula

1 nonillion=1030=1,000,000,000,000,000,000,000,000,000,0001 \text{ nonillion} = 10^{30} = 1{,}000{,}000{,}000{,}000{,}000{,}000{,}000{,}000{,}000{,}000
Where:
  • 103010^{30} = The number 1 followed by 30 zeros (short scale)

Worked Example

Problem: How many zeros does 5 nonillion have, and how do you write it in standard form?
Step 1: One nonillion equals 103010^{30}, which has 30 zeros after the 1.
Step 2: Multiply 5 by 103010^{30} to get 5 nonillion.
5×10305 \times 10^{30}
Step 3: In standard form, write the 5 followed by 30 zeros.
5,000,000,000,000,000,000,000,000,000,0005{,}000{,}000{,}000{,}000{,}000{,}000{,}000{,}000{,}000{,}000
Answer: 5 nonillion = 5×10305 \times 10^{30}, a 5 followed by 30 zeros.

Why It Matters

Scientists use numbers this large when describing things like the mass of the Earth in grams (about 6×10276 \times 10^{27} grams) or counting atoms in large samples. Understanding place-value names like nonillion helps you read and compare numbers written in scientific notation.

Common Mistakes

Mistake: Confusing the short scale and long scale values of a nonillion.
Correction: In the U.S. (short scale), a nonillion is 103010^{30}. In some European countries (long scale), a nonillion means 105410^{54}. Always check which system is being used.