Writing a number too long to say

A made-up town has 2,35,00,000 people. That is hard to read.

The leading part is the number before ×. Move the point left. The leading part must be from 1 to below 10.

The rule

Standard form writes a number as x × 10ʸ. The part x is at least 1 and below 10. The letter y is the exponent. Standard form is also called scientific notation.

Take a whole number of 10 or more. The exponent counts the digits after the first.

• 7,300 has 3 digits after the 7. So it is 7.3 × 10³.
• 60,00,000 has 6 digits after the 6. So it is 6 × 10⁶.
• 2,35,00,000 has 7 digits after the 2. So it is 2.35 × 10⁷.
• A year of 365 days has 3,15,36,000 seconds. There are 7 digits after the 3. So it is 3.1536 × 10⁷.

In standard form, a bigger exponent means a bigger number.

Try the lab to finish this lesson.