What's 29.4983 rounded to the nearest cent

We need to identify what "the nearest cent" is. 

So! 
AB.CD

That is a representation of a number using variables, but we'll just say it's for place values. 

A is in the Tens Place
B is in the Ones Place
C is in the Tenths Place (1/10)
D is in the Hundredths Place (1/100

Since we are talking about money let's put it in relation to a dollar. 

A is in the Ten Dollar Place
B is in the One Dollar Place
C is in the Tenth of a Dollar Place (1/10 of a dollar)
D is in the Hundredth of a Dollar Place (1/100 of a dollar)

So, what is 1/10 of a dollar? 
What amount of money times 10, would get you 1 dollar. Or you can think of it as if you had 10 of one value of money and you got a dollar what is that? A dime. 

Now, what is 1/100 of a dollar? 
What amount of money times 100, would get you 1 dollar. 1 cent (Or it is sometimes called a penny). 

So that means any number beyond the 1/100 of a dollar point (D) will be rounded. If it's the first number after the 1/100 of a dollar is greater than (or equal to) 5 then we round the cent value up. If it is less than 5 we round down. 

$29.4983
So, 9 is our cent place. 8 is greater than 5, so we round 9 up. (Add 1. Since it is 9 it will carry over into the 1/10 of a dollar place)

Our answer is: 
$29.50

Ask google i believe they can you with that question