## Tuesday, January 26, 2010

### Giuseppe's questions for Jan 26 10

3. Use mental math to determine each of the following.

a) 300 % of 2000
100% of 2000 = 2000
300% of 2000 = 6000
To get 300%, you have to multiply the number by 3

b) 1 1/4 % of 60
1% of 60 = 0.6
0.25% of 60 = 0.15
0.6 + 0.15 = 0.75
I know that 1% of 60 is 0.6. So I divided that by 4 (to get 0.25%), and I got 0.15. I added them together and got 0.75

c) 0.1 % of 40
1% of 40 = 0.4
1% ÷ 10 = 0.1%
0.4 ÷ 10 = 0.04
First, I found 1% of 40. Then to get 0.1%, I divided 1% by 10. So that means I have to divide 0.4 by 10 to get 0.1% of 40

4. Use mental math to find the following.

a) 20 % of 60
100% of 60 = 60
100 ÷ 5 = 20
60 ÷ 5 = 12
To get 20% of a number, divide it by 5

b) 250 % of 400
100% of 400 = 400
100 × 2.5 = 250
400 × 2.5 = 1000
To get 250% multiply the number by 2.5

c) 10 1/2 % of 100
100

100% 100
10% 10
1% 1
0.5 0.5

10% + 0.5% = 10.5%
10 + 0.5 = 10.5
If you're trying to find a percent of a hundred, don't work so hard. The answer is the percent they're asking you to find.
Example: 45% of 100 = 45
32.256 % of 100 = 32.256

Hope this helps!!!!! Please comment if you have a question......even though I'm not gonna answer it

carla841 said...

Nice post (:
I understand everything.. but you should use a picture next time so it's easier to understand. Well that's it, nice job.

vanessa 8-41 said...

Good job Giuseppe ! HAHA .. theres really nothing much to say because you explained things well and i understand everything. LOL so yeaah .. good job .

Abigail8-73 said...

Good job Giuseppe! I like how keep the explaination simple and brief. and like Vanessa said, theres nothing really much to talk about/ correct. Good job again! (: