Transcript Unit 2 - rumsonviedteam

Unit 2
Estimation and Computation
Use the following number 5, 678.231 to answer questions 1
and 2.
1. What digit is in the hundreds place?
a. 5
b. 6
c. 3
d. 1
2. What digit is in the tenths place?
a. 2
b. 3
c. 1
d. 7
3. Without using computation, what is 34 *
10,000?
a. 34, 000
b. 3, 400
c. 340, 000
d. 3, 400, 000
Lesson 2-1: Place
Value
Lesson 2-1: Rules of Rounding
• underline place value you are rounding to
• look one place to the right
• 5 or more raise the score
• 4 or less let it rest
• all numbers to the left of underlined number stays the same
Examples:
•
4,827 rounded to the nearest ten is 4,830
•
4,827 rounded to the nearest hundred is 4,800
•
4,827 rounded to the nearest thousand is 5,000
Round each number to the nearest...
number
1
10
100
1,000
3,471.2
3,471
3,470
3,500
3,000
12,673
12,673
12,670
12,700
13, 000
75,485.6
75,486
75,490
75,500
75,000
3,286
3,286
3,290
3,300
3,000
4,249.7
4,250
4,250
4,200
4,000
6,810.8
6,811
6,810
6,800
7,000
Round each number to the nearest...
Number
100
10
1
0.1
0.01
550
549.8
549.81
549.812
500
550
2.8907
X
X
3
2.9
2.89
4,408.93
4,400
4,410
4,409
4,408.9
4,408.9
8.5439
X
X
9
8.5
8.54
Classwork:
1. Begin rounding and place value packet
If time:
2. Math Box 2- 1 (p. 31)
3. Extra Credit
Lesson 2-2: Expanded Notation
Standard Notation
123
39.02
4,916
5.78
302.6
90.005
Expanded Notation
100 + 20 + 3
30 + 9 + 0.02
4,000 + 900 + 10 + 6
5 + 0.7 +
0.08
300 + 2 + 0.6
90 + 0.005
Lesson 2-2: Partial Sums Addition
348
+ 177
2419
+ 536
359
+ 298
2064
+ 382
Keep an open
mind. When
working on your
own, you only
need to use this
strategy for one
problem.
Remember to line up the decimal points
22.62 + 1.7
4.65 + 3.25
5.8 + 2.49
Classwork:
1. Complete journal page 32-33
If time:
2. Math Box 2-2 (p. 34)
3. Extra Credit
Lesson 2-3: Trade First
463
- 275
809
- 537
600
- 397
Keep an open
mind. When
working on your
own, you only
need to use this
strategy for one
problem.
67.35 - 9.59 =
89.67 -
50.30 -
2.98 =
2.42 =
Classwork:
1. Complete journal page 35
If time:
2. Math Box 2-3 (p. 36)
3. Extra Credit
Lesson 2-4: Addition and Subtraction Number Stories
Number Sentences
• Use math symbols instead of words
Open Number Sentences
• contain a variable -letter that
represents a number
• can be true or false
• must use a relation symbol =,
<, >
• must use an operational symbol
+, - *, ÷
Examples
2+2=4
true
6 * 4 > 2 + 8 true
3>9
false
Examples
Solution
(variable equals)
5 + B = 12
B=7
D÷3=8
D = 24
3*4=V
V = 12
120 - C = 60
C = 60
Answer
(unit label)
At breakfast, the temperature
outside was 47˚F. By lunchtime,
the temperature was 63˚F. How
many degrees warmer was it by
lunchtime?
Open number sentence
Solution:
Open number sentence
Answer:
Mary had $32.50 in her savings account.
After she withdrew some money, she
had $17.25 left. How much money did
she withdraw?
Open number sentence
Solution:
The school library has 486
fiction books and 321 non
fiction books. How many
books does the library have in
all?
Solution:
Answer:
Mr. Snow is 49 years old. Her son,
Kevin, is celebrating his 24th birthday
today. Mr. Snow is 6 years older than
Mrs. Snow. How old was Mrs. Snow
when Kevin was born?
Open number sentence
Answer:
Solution:
Answer:
Classwork:
1. Complete journal page 37 & 38
If time:
2. Math Box 2-4 (p. 39)
3. Extra Credit
Lesson 2-5: Statistical Landmarks
Minimum: lowest number
Maximum: highest number
Range: highest number minus the lowest
Mode: the number that occurs most often. There
can be one mode, more than one or no mode.
Example: 1, 5, 4, 3, 3
Example: 3, 4, 4, 5, 6, 6
Example: 3, 4, 5, 6,
Median: the middle number when all the numbers
are arranged in numerical order.
Example: 7, 8, 3, 1, 5
Example: 1, 2, 5, 7, 8, 9
Mean: the average - add all the numbers, divided
by the number of numbers you have.
Example: 3, 4, 5, 6,
Practice:
10, 7, 1, 2, 10, 6, 4, 8
minimum
range
median
maximum
mode
Classwork:
1. Complete journal page 40 - 41
If time:
2. Math Box 2-5 (p. 42)
3. Extra Credit
Displaying Reaction Time in Line Plots
0.11
0.12
0.13
0.14
0.15
0.16
0.17
0.18
0.19
Right Hand Reaction Times (seconds)
0.20
Displaying Reaction Time in Line Plots
0.11
0.12
0.13
0.14
0.15
0.16
0.17
0.18
0.19
Left Hand Reaction Times (seconds)
0.20
Lesson 2-7: Magnitude Estimates
Magnitude Estimates are very rough estimates to a
problem. Round both numbers to greatest place.
56 * 42
16 * 507
32 * 215
1’s
10s
100‘s
1,000s
10,000s
1’s
10s
100‘s
1,000s
10,000s
1’s
10s
100‘s
1,000s
10,000s
13 * 9.2
4.9 * 8.3
1.2 * 0.7
0.01s
0.1s
1’s
1s
10s
0.01s
0.1s
1’s
1s
10s
0.01s
0.1s
1’s
1s
10s
Make a magnitude estimate
73 * 28
1’s
10s
100‘s
1’s
10s
100‘s
1,000s
10,000s
70 * 30 = 2,100
12 * 708
1,000s
10,000s
10* 700 = 7,000
17 * 2.2
0.01s
0.1s
1s
1’s
10s
20* 2 = 40
98 * 105
1’s
10s
100‘s
1,000s
100 * 100 = 10,000
2.6 *3.9
3 * 4 = 12
0.01s
0.1s
1’s
1s
10s
10,000s
Lesson 2-8: Traditional Multiplication - Whole
Numbers
53 * 4 = ______
24 * 7 = ______
19 * 5 = ______
562 * 4 = ______
104 * 3 = ______
710 * 9 = ______
38 * 21 = ______
97 * 34 = ______
52 * 31 = ______
284 * 91 = ______
804 * 37 = ______
619 * 96 = ______
2-8A - Traditional Multiplication - Decimals
53 * 0.8 = ______
9.3 * 0.7 = ______
494 * 0.6 = ______
349 * 0.3 = ______
504* 0.2 = ______
6.4 * 8.6 = ______
7.5 * 1.7 = ______
239 * .28 = ______
Lesson 2-10: Powers of ten