Transcript Decimals

Decimals
Ordering Decimals
• (1)Line Up Decimal Points
• (2)Start at the left and find the first place where the
digits differ. Compare the digits
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(1) 42.1
42.5
(2) 42.1<42.5
1<5
Since 1 is less than 5, we know 42.1 is smaller than 42.5!
Rules for Adding and Subtracting
Decimals
• (1) Line up the numbers by the decimal point.
• (2) Annex zeros to make the same number of
places behind the decimal point in all numbers
in the problem.
• (3) Add or subtract beginning on the far right
side of the problem.
• (4) Place the decimal point in the answer by
bringing the decimal point straight down from
the problem to the answer.
the answer.
Adding and Subtracting Decimals
Rules for Multiplying Decimals
• (1)You do not line up the factors by the decimal.
• (2)Instead, place the number with more digits on
top.
• (3)Multiply
• (4)Count the number of decimal places (from the
right) in each factor.
• (5)Use the total number of decimal places in your
two factors to place the decimal in your product.
Multiplying Decimals
Rules for Dividing Decimals
• (1)If the divisor is not a whole number, move decimal
point to right to make it a whole number and move
decimal point in dividend the same number of
places.
Rules for Dividing Decimals
• (2)Put decimal point directly above decimal point in
the dividend.
• (3)Divide as usual. Keep dividing until the answer
terminates or repeats.