Question 26597
Here's how I would approach it. 
There are obviously 12 months in a year.
The first $900 dollars is the deposit and a month rent.
So, subtract 900 from 6950.
{{{subtraction_cartoon(6950,900)}}}
You should get 6050. 
Since Roberto paid $900 for the first month, he paid $6050 for 11 months with his rent rate.
To find out how much money he paid per month, we would use division. 
{{{$6050/11=$550}}}
{{{highlight($550)}}}
$550 is the monthly rate, and to find out how much the deposit is, use 900 and subtract 550.
You would then get $350 as the first deposit. 
Hope this helps!