Showing posts with label multiplying. Show all posts
Showing posts with label multiplying. Show all posts

Thursday, February 12, 2015

DLMR Part Deux - Captain Zero to the Rescue!

D.L.M.R. - Work Smart, Not Hard!



Work Smart, Not Hard!

Review...

Remember DLMR. Here's some suggestions for DLMR...


Does Love Mean Rules?
Do Like Mother Recommends
Doughnuts Leave Me Retching
Do Like My Rap!
Ducks Like Marshy Rivers
Dogs Like My Rug
Doug Lost My Respect
Digital Listening Mobile Radio
Don't Like My Ride
Down Long Mountain Roads
Detours Leave Me Ranting

When multiplying or dividing numbers containing decimals by 10, 100, 1000, etc., there's no need for long division or multiplication. You need only MOVE the decimal place.



D.L.M.R tells us that when we divide by 10, 100, 

1000, etc., we move the decimal

left 

and when we multiply, we move the decimal 

right

We move one place for every zero (0) in the 10, 100, 1000, 10,000, etc. 

So...2.70 x 100 was 270. How about 2.3 x 10,000?
In the example above, we are multiplying by 10,000. There are 4 zeroes. We need to move the decimal 4 places to the...............................................right. But there is only the one decimal place (the .3). What now?

Captain Zero to the rescue. 
Is he a bird? A plane? No - he's one big zero. You may know him. You may have seen him. He fires blanks. As many as you need. Tack them onto the right of the 2.3




2.3 0 0 0 x 10,000 = 23,000. (Move the decimal place 4 spaces to the right. One for each zero in 10,000.) We move to the right when we multiply.

More examples, covering some trickier problems, will follow in the next postings.

Monday, March 31, 2014

Multiplication Tables in 2 Minutes

You aren't allowed  to take multiplication tables into a GED exam. But what if there was a strategy that would allow you to write them out once the exam had started? In under 2 minutes, no less. Use the multiplication tables then for multiplying, dividing, putting fractions in lowest terms, finding roots and finding square numbers. In under 2 minutes? Impossible you say. See here for the strategy.

Wednesday, March 12, 2014

Multiplication Tables

You cannot take your multiplication tables into the GED exam with you. But what if you could write them out on a spare piece of paper in under 2 minutes. See the Math Doctor on Youtube for the solution. He has the prescription.