Math Shortcuts - visualizing numbers

Visualizing numbers

• 12 days = 1 million seconds
• 1 year = 31 million seconds (about pi * 10 million)
• 30 years = 1 billion seconds
• 30,000 years = 1 trillion seconds

• One “part per million” means an accuracy of 1 second every 12 days. One “part per trillion” means an accuracy of 1 second every 30,000 years.

Source: Mental Math Shortcuts