Decimal Review
Fill in the blanks:
- We use the word
only to indicate the separation between the whole number part and the
fractional part.
- To change a decimal fraction to a decimal number, make sure the number of
digits to the right of the decimal point equals the number of
in the denominator.
- To compare two decimals, start on the left and compare corresponding
digits. Move to the right until the two digits are
.
- To round a decimal to the nearest hundredth, look to see if the digit in
the
place
is
or
larger. If so round up. Otherwise round down.
- To add or subtract two decimals, line the numbers up so that the
are on the same vertical line.
- To multiply two decimals, first multiply the numbers ignoring the decimal
point. Then place the decimal so that the number of digits to the
right of the decimal place is equal to the
of the number of digits to the right of the factors.
- To multiply a decimal by a power of 10 count the
and shift the decimal point this number to the
.
- To divide a decimal by a whole number place the decimal point directly
the decimal point from the dividend.
- To divide a decimal by a decimal, first shift the decimal point of both
the dividend and the divisor until the divisor is a
.
- To convert a fraction to a decimal divide until the remainder becomes
,
, or the
desired number of decimal digits is achieved.
- The order of operations from first to last is
-
-
-
and
-
and
-
- To estimate a messy arithmetic problem, we first round each number to a
number with only one
digit. Then perform the arithmetic.
- In a word problem, some key words that indicate addition are
.
- In a word problem, some key words that indicate subtraction are
.
- In a word problem, some key words that indicate multiplication are
.
- In a word problem, some key words that indicate division are
.