Treat it just like and equation at first. Multiply the 10 on both sides to get rid of it, leaving you with 50 
x. Then on the number line, since there is a line under it, you would make a filled in circle and an arrow pointing towards 51 and beyond
1,129.872 to the nearest hundred is 1,100
Equations is what you have to do
Sallys statement is always true
for example:
-6 + 2 = -4
but if I turn it around
2 - 6 = -4
same answer
-6 -6 = -12
swap around -6 - 6 = 12
same answer
again -3 + 6 = 3
and 6 - 3 = 3
The Decimal number system has following rules.
Suppose you have to write a number 4,567,892 .
2 -ones - (first period)
9-tens - (first period)
8-hundreds - (first period)
7-thousands - (second period)
6-ten thousand- (second period)
5-hundred thousand- (second period)
4-million- (third period)
then comes ten million,hundred million and then Billion.
If a number is given you have to apply commas from left to right after every three places.
So, your number is 9,418.
8-first period
1--first period
4--first period
9- second period
