Phone numbers in the United States are written 555-867-5309 rather than 5558675309 for a reason. Groups of three, three and four are easier to hold.
Key idea
To chunk a number: split it into groups of 3 or 4, and look for groups that already mean something: years, ages, a house number, a repeated digit.
Worked example: Worked example
Chunk 180018121914.
- Twelve digits. Look for years.
- 1800, 1812 and 1914 are all years.
Answer: 1800 · 1812 · 1914: three chunks.
Worked example: Another example
Chunk 365246 into groups that mean something.
- 365 is the days in a year.
- 24 is the hours in a day; 6 is left over.
- Or 365 and 246.
Answer: 365 · 24 · 6 (days in a year, hours in a day, then 6).
Common mistake
Making chunks of one or two digits. Six pairs is still six things to hold; meaningful groups of three or four are better.