mathcalc: Kenneth has $5. He spends g cents everyday. How much money does he have left after one week?
a. Express your answer in cents.
b. Express your answer in dollars.
Hi mathcalc (I liked Jyoti better - never mind, i can't always have everything my own way.)
So he spends g cents every day. That is 7 x g cents every week. and this can be written as 7*g or just 7g (there is an invisable multiply sign)
Since he spends 7g cents and he had 500 cents to start with. He must be left with (500-7g )cents. This is probably the bit you already understood.
Now there are different ways to do this. I am going to do it a little differently from reinout but I can explain his way as well if you want me to.
There are 100 cents in a dollar so
If you have 100cents, that is the same as $1 (100 divided by 100=1)
If you have 200cents, that is the same as $2 (200 divided by 100=2)
If you have 150 cents, that is the same as $1.50 (150 divided by 100=1.5)
if you have m cents, that is the same as m divided by 100cents [and this can be written as (m/100 ) dollars.]
If you have (500-7g) cents that must be the same as (500-7g) divided by 100 (and this can be written as (500-7g)/100 dollars [I got this just by following the pattern]
This looks different from reinout's answer, but it is really the same.
Whenever i get hard problems with horrible numbers or algebra, I try to make it easier by swapping the hard numbers with easy numbers and then see what I would do. When I know what to do with the easy numbers I can then use the same method with the hard numbers.
It makes it easier this way.
Now, would you like me to explain reinout's method as well. Just take a little time to think about mine first. okay?
+201 
+2353 
+201 
+118609 
