 # Computing with Decimals. Adding and Subtracting Decimals.

## Presentation on theme: "Computing with Decimals. Adding and Subtracting Decimals."— Presentation transcript:

Computing with Decimals

Line up the decimal points. 4.6 + 7.23

Line up the decimal points. 4.6 + 7.23 4.60 + 7.23

Fill in with zeros. 4.6 + 7.23 4.60 + 7.23

Fill in with zeros. 4.6 + 7.23 4.60 + 7.23

Add or subtract normally. 4.6 + 7.23 4.60 + 7.23

Add or subtract normally. 4.6 + 7.23 4.60 + 7.23 11 83

Place the decimal point under the other decimal points. 4.6 + 7.23 4.60 + 7.23 11 83

Place the decimal point under the other decimal points. 4.6 + 7.23 4.60 + 7.23 11.83

Line up the decimal points. 12 − 2.46

Line up the decimal points. 12 − 2.46 12 has a decimal point hidden behind it.

Line up the decimal points. 12 − 2.46 12.00 − 2.46

Fill in with zeros. 12 − 2.46 12.00 − 2.46

Fill in with zeros. 12 − 2.46 12.00 − 2.46

Add or subtract normally. 12 − 2.46 12.00 − 2.46

Add or subtract normally. 12 − 2.46 12.00 − 2.46 9 54

Place the decimal point under the other decimal points. 12 − 2.46 12.00 − 2.46 9 54

Place the decimal point under the other decimal points. 12 − 2.46 12.00 − 2.46 9.54

Line up the decimal points. 15.2 − 7.93

Line up the decimal points. 15.2 − 7.93 15.20 −7.93

Fill in with zeros. 15.2 − 7.93 15.20 −7.93

Fill in with zeros. 15.2 − 7.93 15.20 −7.93

Add or subtract normally 15.2 − 7.93 15.20 −7.93

Add or subtract normally 15.2 − 7.93 15.20 −7.93 7 27

Place the decimal point under the other decimal points. 15.2 − 7.93 15.20 −7.93 7 27

Place the decimal point under the other decimal points. 15.2 − 7.93 15.20 −7.93 7.27

 Line up the decimal points.  Fill in with zeros.  Add or subtract normally.  Place the decimal point under the other decimal points. 24.5 – 13

 Line up the decimal points.  Fill in with zeros.  Add or subtract normally.  Place the decimal point under the other decimal points. 16.8 + 4.72

 Line up the decimal points.  Fill in with zeros.  Add or subtract normally.  Place the decimal point under the other decimal points. 143.2 + 4.18

 Line up the decimal points.  Fill in with zeros.  Add or subtract normally.  Place the decimal point under the other decimal points. 35 – 4.5

 Line up the decimal points.  Fill in with zeros.  Add or subtract normally.  Place the decimal point under the other decimal points. 2.14 + 8.4

 Line up the decimal points.  Fill in with zeros.  Add or subtract normally.  Place the decimal point under the other decimal points. 9 – 3.65

 Line up the decimal points.  Fill in with zeros.  Add or subtract normally.  Place the decimal point under the other decimal points. 4.02 + 0.75

 Line up the decimal points.  Fill in with zeros.  Add or subtract normally.  Place the decimal point under the other decimal points. 8.4 – 2.13

 Line up the decimal points.  Fill in with zeros.  Add or subtract normally.  Place the decimal point under the other decimal points. 5 + 0.52

 Line up the decimal points.  Fill in with zeros.  Add or subtract normally.  Place the decimal point under the other decimal points. 12 – 0.68

Multiplying Decimals

Remove any extra zeros. 0.54 x 1.20.54 x 1.2 0.064 x 2.09.064 x 2.09 340 x 0.50 340 x.5 4.03 x 6.304.03 x 6.3

Remove any extra zeros. 0.70 x 2.05.7 x 2.05 0.003 x 1.10.003 x 1.1 500 x 2.70 500 x 2.7 0.082 x 0.09.082 x 0.09

Find the number that has the most digits NOT INCLUDING zeros on the front..54 x 1.2 2 digits

Find the number that has the most digits NOT INCLUDING zeros on the front..064 x 2.09 2 digits3 digits

Find the number that has the most digits NOT INCLUDING zeros on the front. 340 x.5 3 digits1 digit

Find the number that has the most digits NOT INCLUDING zeros on the front. 4.03 x 6.3 3 digits2 digits

Find the number that has the most digits NOT INCLUDING zeros on the front..7 x 2.05 1 digit3 digits

Find the number that has the most digits NOT INCLUDING zeros on the front..003 x 1.1 1 digit2 digits

Find the number that has the most digits NOT INCLUDING zeros on the front. 500 x 2.7 3 digits2 digits

Remove any extra zeros. 0.47 x 0.2

Remove any extra zeros. 0.47 x 0.2

Find the number that has the most digits NOT INCLUDING zeros on the front. 0.47 x 0.2

Find the number that has the most digits NOT INCLUDING zeros on the front. 0.47 x 0.2 2 digits

Find the number that has the most digits NOT INCLUDING zeros on the front. 0.47 x 0.2 2 digits1 digit

Put that number on top lining up the right side of the problem. 0.47 x 0.2 2 digits1 digit

Put that number on top lining up the right side of the problem..4 7 x.2

Multiply normally..4 7 x.2

Multiply normally..4 7 x.2 9 4

Count the total number of decimal places in the problem..4 7 x.2 9 4

Count the total number of decimal places in the problem..4 7 x.2 9 4 2 decimal places

Count the total number of decimal places in the problem..4 7 x.2 9 4 2 decimal places +1 decimal place

Count the total number of decimal places in the problem..4 7 x.2 9 4 2 decimal places +1 decimal place 3 decimal places

Put that many decimal places in the answer..4 7 x.2 9 4 2 decimal places +1 decimal place 3 decimal places

Put that many decimal places in the answer..4 7 x.2 9 4 2 decimal places +1 decimal place 3 decimal places 1 decimal place

Put that many decimal places in the answer..4 7 x.2 9 4 2 decimal places +1 decimal place 3 decimal places 2 decimal places

Put that many decimal places in the answer..4 7 x.2.0 9 4 2 decimal places +1 decimal place 3 decimal places

Put that many decimal places in the answer..4 7 x.2.0 9 4

Remove any extra zeros. 3.45 x 0.004

Remove any extra zeros. 3.45 x 0.004

Find the number that has the most digits NOT INCLUDING zeros on the front. 3.45 x 0.004

Find the number that has the most digits NOT INCLUDING zeros on the front. 3.45 x 0.004 3 digits

Find the number that has the most digits NOT INCLUDING zeros on the front. 3.45 x 0.004 3 digits1 digit

Put that number on top lining up the right side of the problem. 3.45 x 0.004 3 digits1 digit

Put that number on top lining up the right side of the problem. 3. 4 5 x. 0 0 4

Multiply normally. 3. 4 5 x. 0 0 4

Multiply normally. 3. 4 5 x. 0 0 4 1 3 8 0

Count the total number of decimal places in the problem. 3. 4 5 x. 0 0 4 1 3 8 0

Count the total number of decimal places in the problem. 3. 4 5 x. 0 0 4 1 3 8 0 2 decimal places

Count the total number of decimal places in the problem. 3. 4 5 x. 0 0 4 1 3 8 0 2 decimal places +3 decimal places

Count the total number of decimal places in the problem. 3. 4 5 x. 0 0 4 1 3 8 0 2 decimal places +3 decimal places 5 decimal places

Put that many decimal places in the answer. 3. 4 5 x. 0 0 4 1 3 8 0 2 decimal places +3 decimal places 5 decimal places

Put that many decimal places in the answer. 3. 4 5 x. 0 0 4 1 3 8 0 2 decimal places +3 decimal places 5 decimal places 1 decimal place

Put that many decimal places in the answer. 3. 4 5 x. 0 0 4 1 3 8 0 2 decimal places +3 decimal places 5 decimal places 2 decimal places

Put that many decimal places in the answer. 3. 4 5 x. 0 0 4 1 3 8 0 2 decimal places +3 decimal place 5 decimal places 3 decimal places

Put that many decimal places in the answer. 3. 4 5 x. 0 0 4 1 3 8 0 2 decimal places +3 decimal place 5 decimal places 4 decimal places

Put that many decimal places in the answer. 3. 4 5 x. 0 0 4.0 1 3 8 0 2 decimal places +3 decimal place 5 decimal places

Put that many decimal places in the answer. 3. 4 5 x. 0 0 4. 0 1 3 8 0

Remove any extra zeros. 3.40 x 1.98

Remove any extra zeros. 3.40 x 1.98

Find the number that has the most digits NOT INCLUDING zeros on the front. 3.40 x 1.98

Find the number that has the most digits NOT INCLUDING zeros on the front. 3.40 x 1.98 2 digits

Find the number that has the most digits NOT INCLUDING zeros on the front. 3.40 x 1.98 2 digits3 digits

Put that number on top lining up the right side of the problem. 3.40 x 1.98 2 digits3 digits

Put that number on top lining up the right side of the problem. 1. 9 8 x 3. 4

Multiply normally. 1. 9 8 x 3. 4

Multiply normally. 1. 9 8 x 3. 4 7 9 2

Multiply normally. 1. 9 8 x 3. 4 7 9 2 5 9 4 0

Multiply normally. 1. 9 8 x 3. 4 7 9 2 5 9 4 0 6 6 3 2

Count the total number of decimal places in the problem. 1. 9 8 x 3. 4 7 9 2 5 9 4 0 6 6 3 2

Count the total number of decimal places in the problem. 1. 9 8 x 3. 4 7 9 2 5 9 4 0 6 6 3 2 2 decimal places

Count the total number of decimal places in the problem. 1.9 8 x 3. 4 7 9 2 5 9 4 0 6 6 3 2 2 decimal places +1 decimal place

Count the total number of decimal places in the problem. 1. 9 8 x 3. 4 7 9 2 5 9 4 0 6 6 3 2 2 decimal places +1 decimal place 3 decimal places

Put that many decimal places in the answer. 1. 9 8 x 3. 4 7 9 2 5 9 4 0 6 6 3 2 2 decimal places +1 decimal place 3 decimal places

Put that many decimal places in the answer. 1. 9 8 x 3. 4 7 9 2 5 9 4 0 6 6 3 2 2 decimal places +1 decimal place 3 decimal places 1 decimal place

Put that many decimal places in the answer. 1. 9 8 x 3. 4 7 9 2 5 9 4 0 6 6 3 2 2 decimal places +1 decimal place 3 decimal places 2 decimal places

Put that many decimal places in the answer. 1. 9 8 x 3. 4 7 9 2 5 9 4 0 6.6 3 2 2 decimal places +1 decimal place 3 decimal places

Put that many decimal places in the answer. 1. 9 8 x 3. 4 7 9 2 5 9 4 0 6.6 3 2

 Remove any extra zeros.  Find the number that has the most digits NOT INCLUDING zeros on the front.  Put that number on top lining up the right side of the problem.  Multiply normally.  Count the total decimal places in the problem.  Put that many decimal places in the answer.