Transcript UNIT 12 DECIMALS

UNIT 12
DECIMALS
NUMERATION
4TH GRADE GIFTED
VOCABULARY
ones
tens
one hundred
number line
1. The number 438,572 has a 7 in
the __________ place.
2. Ten tens are equal to ______.
3. A _______ can be used to
show numbers in order using
a scale.
Comparing Numbers
>
<
=
1,909
1,999
43,627
43,167
629,348
629,348
455,311
455,331
101,101
101,011
95,559
95,555
Order these numbers from greatest to least.
1. 3,687
2. 41,101
3. 4,593
4. 678,912
3,867
3,678
41,011
4,395
3,768
41,110
4,595
678,921
41,001
4,359
687,999
678,291
Order from least to greatest.
15,420
154,200
1,542
543,897
54,380
534,978
Use a decimal model to show
1.6 pounds.
A decimal model can also show
1.6 hundredths.
Write the decimal: 1.64
Standard form:
Expanded form:
Word form:
Write the expanded form and word form.
3.91
6.8
1.09
2.3
Write the decimal for each.
What would the fraction be?
Write the decimal shown.
Write the fraction.
Write the number in word and give the
value of each red digit.
2.47 ________________________
3.19 ________________________
23.79 ________________________
0.78 ________________________
1.8 ________________________
14.1 ________________________
9.05 ________________________
Write a number that has a 4 in the tens
place and a 5 in the hundredths place.
_________________________________
The capybara can grow to be 1.3
meters long. Write 1.3 in expanded
form and in word form.
___________________
___________________
The Green Darner is one of the
largest dragonflies on Earth.
It weighs about four hundredths
of an ounce. Write the weight in
standard form.
Use the decimal model to explain
why 0.08 is less than 0.1
Write the word form and tell the value
of each red digit.
2.300 __________________________
9.027 __________________________
1.982 __________________________
6.17 __________________________
4.983 __________________________
8.46 __________________________
Write each number in standard form.
6 + 0.6 + 0.03 + 0.007
3 + 0.3 + 0.009
9 = 0.2 + 0.04 + 0.008
Write two decimals that are
equivalent to the decimal below.
2.200 _________________________
8.1
_________________________
9.50 _________________________
Bella finished a race in 2.6
hours, and Sophia finished the
same race in 2.600 hours.
Which runner finished the
race first?
Alex is buying juice at the
market. He has $9, and each
bottle of juice costs $2.
Does he have enough money to
buy 5 bottles of juice? Explain.
Nikki made 19 pancakes for
breakfast. She took 7 and gave
an equal number to her dad and
mom. How many pancakes did
each of her parents get?
The Borneo stick insect
has a total length, including
its legs, of 21.5 inches.
Name two decimals that are
equivalent to 21.5
Worker leafcutter ants can
measure 0.5 inch.
Write three other ways to write
0.5 inch.
Decimal to Whole Number
Connection
thousands
hundreds
tens
ones
.
1,000
100
10
1
.
5
3
4
2
.
tenths
hundredths
thousandths
0.1
0.01 0.001
1/10 1/100 1/1000
4
3
5
Write the place value for the
red digit.
34.67 _____________________
856.472 _____________________
486.359 _____________________
6,095.375 _____________________
Write the number that is ten
times as many.
1.
_____________________
0.01 _____________________
100.
_____________________
0.001_____________________
A telephone worker used
340.75 feet of cable.
What is the place value of the
5 in 340.75 ?
3 4 0.7 5
The grid below shows one hundred equal parts.
Each part is equal to one hundredth.
How many hundredths are in
one tenth?
Write the place value for each bold digit.
572.67
2,368.795
1,435.889
9,654.328
601.65
1,754.709
4,597.624
6,332.470
2,867.435
9,555.392
1,843.2
5,642.437
Write the number that is ten times as many.
0.07
40
0.008
0.9
35
0.6
0.03
500
8.0
70.1
250
1.005
There are 100 fiction books in
the classroom library. The
school library has ten times as
many fiction books. What is the
number of fiction books in the
school library?
Ryan and Colin collected aluminum cans
for the school recycling project.
Look at the chart to find out who
collected the most cans. Find the
difference between the number of
cans collected.
RYAN
1,352
COLIN
1,329
Kiley baked 3 times as many
muffins as Kayla for the
school bake sale. If Kayla
baked 36 muffins, how many
did Kiley bake?
Kayla
Kiley
36
Mrs. B has 6 gallons of gas in her car.
Her tank can hold 15 gallons.
Will Mrs. B need more or less than 10
gallons of gas to fill her tank?
_______
If gas is $3.49 per gallon, how much will
it cost to fill up the tank?
Ethan found two shells that are the same
shape but are different sizes.
One weighs 0.01 pound and the other
weighs ten times as much.
How much does the heavier shell weigh?
Charlie and Kohle are discussing
the value of the first 1 and the
second 1 in the number 4.115
Charlie thinks the first 1 has
greater value than the second.
Is he correct?
Decimals on the number line.
0
1
2
3
4
Locate 1.90 on the number line.
Decimals on the number line.
0
1
2
3
4
Locate 2.3 on the number line.
Locate 4.1 on the number line.
Decimals on the number line.
0
1
2
3
4
Locate 0.8 on the number line.
Locate 3.4 on the number line.
Name the points on the number line.
A
0
1
B
C
2
D
3
A
B
C
D
4
Mark each point on the number line.
0
1
2
3
2.6
1.3
0.4
3.9
4
Decimals on the number line.
A
B
C
7
D
8
E F
9
A
B
C
D
E
F
Decimals on the number line.
A
B
C
2
A
D
D
E
3
B
E
4
C
F
F
Decimals on the number line.
7.00
7.30
7.60
Decimals on the number line.
10
11
12
13
14
Locate 10.85 on the number line.
Locate 12.42 on the number line.
Decimals on the number line.
0
1
2
3
4
How many tenths between 1 and 2?
How many hundredths between 1 and 2?
Decimals on the number line.
7
8
9
Name two decimals between
8.4 and 8.6
Sea level at Key West is rising
about 1.8 millimeters per year.
What is the place value of the
digit 8 in this number?
How do you round to the nearest tenth?
What is 211.98 rounded to the
nearest tenth?
Look at the tenths place 211.98
Look at the digit to the right. 211.98
211.98 rounds to 212.0
Since the digit is 8, the digit in the
tenths place increases by 1.
Round 68.142 to the nearest
hundredth.
Look at the hundredths place 68.142
Look at the digit to the right 68.142
Since 2 < 5, the hundredths
digit stays the same.
68.142 rounds to 68.14
Round each to the place of the
underlined digit.
17.23
19.805
49.562
67.591
Round each to the place of the underlined digit.
60.82
88.3
2.283
0.695 72.564
41.483 0.819 147.61 857.95 591.95
312.12 4.108 1009.1 64.93
7.452
99.99
12.55
78.61
38.8
230.9
Name 3 decimals that when
rounded to the nearest tenth,
round to 7.8
Which of these decimals does
NOT round to 6?
5.71
5.91
6.82
6.249
6.001
Megan wanted to know the total mass of two
pieces of volcanic rock. The first piece had a
mass of 4.99 grams and the second had a
mass of 2.85 grams.
Megan wants to record the combined masses
of the two pieces of volcanic rock to the
nearest gram. Is 4.0 + 2.9 a reasonable
estimate of the masses to the nearest gram?
Lauren was asked to round 89.367
to the nearest hundredth. She
answered 89.40
Is she correct?
Explain
According to Jimmy’s rain
gauge, it had rained 2.28
inches in 24 hours.
What is 2.28 rounded to the
nearest tenth?
What is 2.28 rounded to the
nearest whole number?
Landon filled the car with 8.53
gallons of gasoline. To the
nearest tenth of a gallon, how
much gasoline did Landon
put in the car?
Maggie’s dog weighs
5.521 pounds.
To the nearest whole number,
how much does Maggie’s
dog weigh?
Autumn jogs 12 miles each
week. How many miles does
Autumn jog in 1 year?
Which ones don’t belong?
3.6
4.2
4.1
3.9
4.4
3.8
4.6
3.5
4.8
3.7
4.3
3.2
Ari bought 10 bagels.
Three-tenths of the bagels are
plain and the rest are cinnamon.
How many cinnamon bagels
are there?
According to MapQuest,
Bella and her family need to
travel 53.19 miles to get to her
grandmother’s house. What is
this distance rounded to the
nearest mile?
Venn diagrams are very useful to show how different
data belong to groups. Remember, if the data
overlaps, the data belongs in more than one group.
2
4
8
10
14
20
2
16
6
12
3
9
18
15
3
Which numbers in the Venn are multiples or 2?
Which are multiples of 3?
Which are multiples of both 2 and 3?
Add the numbers 21, 22, and 24 to the Venn.
2
4
8
10
14
20
16
6
12
18
3
9
15
Comparing Decimals
>
=
<
48.64
48.68
9.27
3.692
3.697 7.21
9.2
7.203
Use the number line to help you
compare
2.453 and 2.458
2
3
COMPARE
5.733
0.890
0.89
4.953
4.951
1.403
0.7
0.57
0.23
1.1
1.10
3.406
5.693
9.70
9.71
1.4
3.074
3.740
0.32
6.562
6.559
3.4
6.57
6.571
The most important thing you
must remember is to
LINE UP THE
DECIMAL POINTS
before you do ANYTHING!
4.601
34.8
2.79 1.02
+3.280 - 12.4
x .35 : .10
Sophia earns $4 per week doing
chores. If one flower costs
$2, how many flowers can
Sophia buy if she saves for
three weeks?
Which number is less than
0.125?
0.5
0.13
0.119
0.2
0.124
0.126
Alex said the numbers
3.04, 0.43, and 2.4
are in order from greatest to
least. Is he correct or do the
numbers need to be rearranged?
Nikki has a bag of 500
nickels which weigh 5.5 pounds.
A bag of 200 half dollars
weighs 5 pounds.
Which weighs more?
Ryan said the numbers 7.37,
7.36, 2.59, and 2.95 were in
order from greatest to least.
Is he correct. Explain.
Help Kiley put these
numbers in order from least
to greatest.
0.352
0.04
0.28
0.15
0.096
0.09
0.79
0.12
0.186
Look at the line below.
If you start at 0.4 and walk 0.8
mile, where will you end up on
the line?
0
0.4
Look at the drawing below.
How can you use the mark on
the line to find where 1.0
should be located?
0
0.2
Kayla needs to redesign a
banner for field day. She wanted
her banner to be 2 feet long.
Kayla marked 0.5 foot on her
drawing. How can she use this
distance to find 2 feet?
0
0.5
Jimmy jogged 1.7 miles one
morning. Ethan jogged
1.75 miles that same day.
Who jogged the farthest?
Explain.
Colin wrote a four-digit
number. He used the digits 2,
4, 6, and 8. How many different
four-digit numbers could
Colin have written?
Kohle has half as many
brothers as Charlie. If Kohle
has “K” brothers, how many
brothers does Charlie have?
Write an algebraic expression.
Maggie has 3 coin purses with
58 coins in each. How many coins
does Maggie have?
Lauren and Bekah sold
45 boxes of Girl Scout cookies.
They deliver “C” boxes each
day for 5 days.
Solve.
Maggie wants to find which
number is equal to three and
twenty-two thousandths?
Which should she pick?
3.2200
3,22
3.022
3.0022
Megan is cooking 4.619
pounds of spaghetti.
To the nearest hundredth, how
many pounds of spaghetti is
Megan cooking?
4.60 pounds
4.62 pounds
5 pounds
4.7 pounds
Landon is trying to find which
number has a 5 in the
thousandths place.
9,562,791.1
825.858
385.59
176.245
Ari is making a banner for
Girl Scouts. She marked 0.5
on a piece of banner paper.
What should she do to find
1.0?
Find the distance halfway to 1
Find the 0.5 and move right 0.5 more
Double the distance from 0.5
Move 0.5 to the left of 0.5
Autumn is mailing a present
that weighs 15.683 pounds.
To the nearest tenth, how
many pounds does the
package weigh?
What is the place value of the
9 in 4,602.791?
Ones
Tenths
Hundredths
Thousands
Put these numbers in a
Place Value chart.
Now put them in order from
least to greatest.
90.49
90.4 9.149
Which of these statements is
true?
5.352 < 5.350
5.350 = 5.360
5.353 < 5.360
5.358 > 5.360
Which of the following are
less than 8.007
8.002
8.200
8.020
8.022
Put each set of numbers in
order from greatest to least.
9.8
9.78
9.87
9.87
9.8
9.78
9.78
9.87
9.9
9.9
9.8
9.98
What is ten times as many as
the number 0.04?
0.004
0.04
4.0
0.4
Which decimal is shown in
the model below?
2.0
2.96
2.40
2.04