studying for the asvab relearning how to do math by hand

[laureng]

Ive got an asvab book and it helps but doesnt show all of the steps needed to solve the problem, I understand the concepts but get stuck on the smaller details like division and multiplication

Frederick earns $1500 per month at his job, but 28% of that amount is deducted for taxes- what is the monthly take home pay?

I get that I am supposed to solve for the take home pay

T= 1500 -(1500x 0.28)

but heres where I get stuck- when I do 1500 x 0.28 by hand I kept ending up with 350, when I did the answer with calculator and know its 420- what am i doing wrong??

 

[tkhunny]

2*1500 = 3000

8*1500 = 1200

Not sure without showing your work.

 

[lookagain]

Frederick earns $1500 per month at his job, but 28% of that amount is deducted for taxes- what is the monthly take home pay?

I get that I am supposed to solve for the take home pay

T= 1500 -(1500x 0.28)

but heres where I get stuck- when I do 1500 x 0.28 by hand I kept ending up with 350, when I did the answer with calculator and know its 420- what am i doing wrong??

This is my way:


\(\displaystyle \ \ \ \ \ 1500\)
\(\displaystyle \ \ \ \ \ \ 0.28\)
--------
\(\displaystyle \ \ \ \ 12000\)
\(\displaystyle \ \ \ \ 3000\)
--------
\(\displaystyle \ \ \ 420.00\)



How did you attempt it?


=-=-=-=-=-=-=-=-=-=-=-

2*1500 = 3000

8*1500 = 12000

 

[JeffM]

Ive got an asvab book and it helps but doesnt show all of the steps needed to solve the problem, I understand the concepts but get stuck on the smaller details like division and multiplication

Frederick earns $1500 per month at his job, but 28% of that amount is deducted for taxes- what is the monthly take home pay?

I get that I am supposed to solve for the take home pay

T= 1500 -(1500x 0.28)

but heres where I get stuck- when I do 1500 x 0.28 by hand I kept ending up with 350, when I did the answer with calculator and know its 420- what am i doing wrong??

Let's start with basics:

\(\displaystyle 0.28 = \dfrac{28}{100} = \dfrac{20}{100} + \dfrac{8}{100} \implies\)

\(\displaystyle 1500\ X\ 0.28 = 1500\ X\ \dfrac{20}{100} + 1500\ X\ \dfrac{8}{100} = 20\ X\ 15 + 8\ X\ 15 = 300 + 120 = 420.\)

Does that help?

 

[tkhunny]

Correction for TKHunny

Right. I was using my sliderule and choked on the order of magnitude.