Chapter 3: Adding and Subtracting Decimals · 3.8 Adding Decimals & 3.9 Subtracting Decimals Use...
Transcript of Chapter 3: Adding and Subtracting Decimals · 3.8 Adding Decimals & 3.9 Subtracting Decimals Use...
Chapter 3: Adding and
Subtracting DecimalsMAFS.5.NBT.1.1,MAFS.5.NBT.1.3 ,
MAFS.5.NBT.1.4 , MAFS.5.NBT.2.7
Ch 3 Vocabulary Words
1. Benchmark - A familiar number used as a point of reference Example:
2. Place value - The value of each digit in a number based on the location of the digit
3. Tenth- One of ten equal parts Example: 0.7 = seven tenths or 7/10
4. Hundredth- One of 100 equal parts Examples: 0.56, ___ 56/100 , fifty-six hundredths
5. Round- To replace a number with one that is simpler and is approximately the same size as the original number Example: 114.6
rounded to the nearest ten is 110 and to the nearest one is 115.
6. Sequence- an ordered list of numbers
7. Term- a number in a sequence
8. Thousandth- One of one thousand equal parts Example: 0.006 = six thousandths or 6/1,000
3.1 Thousandths
Thousandths are smaller parts than hundredths. If one hundredth is divided into
ten equal parts, each part is one thousandth.
3.1 Continued
1. 0.6 is 10 times as much as __
1. 0.008 is 1/10 of __
https://www.youtube.com/watch?v=UEi3crjbCaE
Decimal Ten times as much as 1/10 of
0.03 0.3 0.003
0.7
0.01
3.2 Place Value of Decimals
You can use a place-value chart to understand decimals. Whole numbers are to
the left of the decimal point. Decimals are to the right.
Standard Form: 1.726
Word Form: one and seven hundred twenty-six thousandths
Expanded Form: (1x1) + (7 x 1/10) + (2 x 1/100) + (6 x 1/1000)
Tens Ones Decimal
Point
Tenths Hundredths Thousandths
Standard 1 7 2 6
Expanded 1x1 7 x 1/10 2x1/100 6x1/1000
Decimals 1.0 0.7 0.02 0.006
3.2 Continued
Decimal Value of
underlined digit
Word Form Expanded Form
0.287 0.2 or two tenths two hundred
eighty-seven
thousandths
(2 x 1/10) + (8 x 1/100) +
(7 x 1/1000)
6.359
2.704
Engage NY Module 1 Lesson 5
3.3 Compare and Order Decimals
How can you use place value to compare and order decimals?
3.3 On Your Own
Compare. Write <, >, or =.
1. 8.673 8.637 2. 1.036 1.306
Name the greatest place-value position where the digits differ. Name the greater number.
3. 3.579; 3.564 4. 9.572; 9.637
Order from least to greatest.
5. 2.007; 2.714; 2.09; 2.97 6. 1.703; 1.037; 1.37; 1.073
Round to the underlined digit.
7. 0.428 8. 3.19
3.5 Decimal Addition & 3.6 Decimal Subtraction (using
models) Videos: https://www.youtube.com/watch?v=Mxo9EVFVGMU &
https://www.youtube.com/watch?v=0sjLdohzEVo
Addition with models
1) 1.37 + 1.85 =
Subtraction with Models
2) 2.82 - 1.47 =
Drawing Models
1. 0.9 - 0.2 =
2. 0.5 +0.12 =
3.8 Adding Decimals & 3.9 Subtracting Decimals
Use place value to add and subtract decimals. Make sure to line the decimals up
first and then solve your problem.
Estimate. Then find the sum or difference.
1. 5.83 Estimate: ____ 2. 12.3 Estimate: ____
- 2.18 + 4.9
3. Find the sum. seven and twenty-five hundredths added to nine and four tenths
4. Find the difference. three and seventy-two hundredths subtracted from five
and eighty-one hundredths
5. n - 6.47 = 4.32
3.11 Adding and Subtracting Money
How can the strategy make a table help
you organize and keep track of your bank
account balance?
1. Sara wants to buy a bottle of apple juice from a
vending machine. She needs exactly $2.30. She
has the following bills and coins:
Make and complete a table to find all the ways Sara
could pay for the juice. First, draw a table with a
column for each type of bill or coin. Next, fill in your
table with each row showing a different way Sara can
make exactly $2.30.
$1 Qtrs Dimes Nickel
s
Value
3.11 Cont’d
2. Mr. and Mrs. Daniels are going to Tokyo next summer. Each week they record
the value of one Yen in U.S. dollars, The table shows the data she has recorded
so far.
For which two weeks was the value of 1 Yen the same when rounded to the
nearest hundredth?
Week Value of 1 Yen (in
U.S.
1 0.096
2 0.091
3 0.099
4 0.089
3.12 Continued
2. 4.19 + 0.58
3. 38.44 − 25.86
4. 5.7 + 2.25 + 1.3
Metric Conversions - K.H.D. (B) D.C.M.
Kilo- x 1000
Hecto- x 100
Deca- x 10
Base (meter, liter, gram) x 1
Deci- x 1/10
Centi- x 1/100
Milli- x 1/1000
Flocabulary Song https://www.flocabulary.com/unit/metric-system/video/
Metric conversions - Your Turn