The girls are watching Schoolhouse Rock (which is one of the best things ever invented, IMHO), and I was reminded of this fun, easy math fact...
When I was a kid (okay, admittedly even now) I was never good with multiplication. Nowadays, students are encouraged to use calculators, but I still think it's important to know how to do math in your head (even if it's only basic math). The "nines" times table was always particularly hard for me. If only I'd known about these two magic little words:
Digit SumIn the "nines" times table, one easy way to know if you're doing your math correctly is that the numbers of the digit sum (meaning the answer) of a product of nine, when added together, will ALWAYS equal 9.
Example:
9 X 2 = 18 (1 + 8 = 9)
9 X 3 = 27 (2 + 7 = 9)
9 X 4 = 36 (3 + 6 = 9)
It even works with
larger numbers (obviously it gets a little more complicated, you need to be able to do somewhat more abstract math, but it does still work):
43 X 9 = 387 (3 + 8 + 7 = 18; 1 + 8 = 9)
72 X 9 = 648 (6 + 4 + 8 = 18; 1 + 8 = 9)
Even really
large numbers:
94256 X 9 = 848304 (8 + 4 + 8 + 3 + 0 + 4 = 27; 2 + 7 = 9)
Obviously you're not going to normally be multiplying numbers quite that large in your head...but it's nice to know how to check your math easily.
Okay, so God was referring to a different kind of "multiplying". I came up with the title, liked it, and stuck with it. So sue me.
Why yes, I AM a dork. Thanks for noticing!