I don't know if this is a new problem or not, but I don't know how to do it quickly. I can use the regular squaring method, but is there an easier way. 707^2 = 499849. How? Thanks, Jim
There is an easy way to square 707. In general if you have (101a)^2 you can expand this to be 10201 x a^2. This makes the problem very easy. All you have to do is:
Write a^2.
Write 2 x a^2.
Write a^2.
In the problem (707)^2 we can expand this to be 49 x 10201. The answer is 49, 2x49, 49 or 49 98 49 or 499849.
A word of caution: If the 'a' is greater than 7, you will have to carry into the first digits.
Ex [1] (909)^2 = __________.
9^2 = 81.
The answer is 81, 2 x 81, 81. But 2 x 81 = 162. So you need to write 62 and carry the 1.
