Archive for the ‘Uncategorized’ Category
How do you find a power of 2 that begins with a 9?
Posted by: Gary Ernest Davis on: November 13, 2010
The problem of finding a power of 2 that begins with a 9 was posed in the recent #mathjams conference in the UK. I tweeted: republicofmath 2^n begins with 9 for n = 53, 63, 73, 83, 93, 156, 166, 176, 186, 249, 259, 269, 279, 289, 352, 362, 372, 382, 445, 455, 465 … […]
What does it mean to know a number? Pi for elementary teachers
Posted by: Gary Ernest Davis on: November 12, 2010
Area and “amount of stuff” The area of a region is often colloquially thought of as the “amount of stuff” in that region. This is not a good way of thinking about area because it leads to odd thinking such as the area of a region does not change if the perimeter changes “because the […]
