2.2 adding whole # and decimals.notebook
September 30, 2011
Everyday Math
2.2
Unit 2 Lesson 2
Mental Math and Reflexes
Addition of Whole
Numbers and Decimals
Write these numbers in
expanded notation on your slate:
0.52
Objective: To review place-value
concepts and the use of the
partial-sums and column-addition
methods.
Reminder
Expanded notation
expresses a number
as the sum of the
values of each digit.
52
0.35
35
TLG Page 81
Getting Started
Lesson 2.2 Mental Math and Reflexes
2.2
Everyday Math
2.2
Everyday Math
Place-Value Chart
Mental Math and Reflexes
1
10 *
Write these numbers in
expanded notation on your slate:
1,000s
thousands
467
1
10 *
100s
hundreds
1
10 *
10s
tens
1
10 *
1s
ones
.
1
10 *
0.1s
tenths 1
10 *
0.01s
hundredths 0.001s
thousandths Reminder
Expanded notation
expresses a number
as the sum of the
values of each digit.
0.241
241
Think of one true statement you could make
about the base-ten system for numbers.
162
TLG Page 86
TLG Page 86
Getting Started
Part 1
Mental Math and Reflexes
Place­Value Chart
2.2
Everyday Math
2.2
Everyday Math
Place-Value Chart
1
10 *
1,000s
thousands
100s
hundreds
1
10 *
10s
tens
1
10 *
1s
ones
1
10 *
.
Place-Value Chart
1
10 *
0.1s
tenths 1
10 *
1
10 *
0.01s
hundredths 0.001s
thousandths Pull
Each place has a value that is 10 times the
value of the place to its right.
1,000s
thousands
100s
hundreds
1
10 *
1
10 *
10s
tens
1s
ones
1
10 *
.
1
10 *
0.1s
tenths 1
10 *
0.01s
hundredths 0.001s
thousandths What is the value of the digit 2 in each of these
numbers? Can you prove your answer using the chart?
a. 20,006.8
Each place has a value that is one-tenth
the value of the place to its left.
b. 0.02
c. 34.502
SRB p. 30
TLG p.86
Part 1
TLG Page 86
Part 1
Place­Value Chart
Place­Value Chart
1
2.2 adding whole # and decimals.notebook
September 30, 2011
Everyday Math
2.2
First
Write the numbers 348 and 177
in expanded notation.
Then
Open your SRB to page 13 and read the
section on the partial-sums method.
TLG Page 87
Part 1
Sep 20­2:50 PM
Expanded Notation
Everyday Math
2.2
Expanded notation
First
Partial Sum Method
300 + 40 + 8
+
400 + 110 + 15
10s
1s
3
4
8
7
7
4
0
0
Add the 100s.
525
100s
+ 1
100 + 70 + 7
510 + 15
2.2
Everyday Math
348 + 177= ?
1
Add the 10s.
Add the 1s.
Add partial sums.
5
1
0
1
5
2
5
Write the numbers 4.56 and 7.9
in expanded notation.
Then
Open your SRB to page 35 and read the
section on the partial-sums method when
you have decimals.
SRB p. 13
TLG P. 87
Part 1
TLG Page 87
Part 1
Partial Sum Method
Expanded Notation
2.2
Everyday Math
Expanded notation
+
Column-Addition Method
Each column of numbers is added separately in any order.
Partial Sum Method
4 + 0.5 + 0.06
1s
7 + 0.9
4 .
5
6
+ 7 .
9
0
11 .
0
0
Add the tenths.
1 .
4
0
Add the hundredths.
0 .
0
6
12 .
4
6
11 + 1.4 + 0.06
12.4 + 0.06
12.46
2.2
Everyday Math
348 + 177= ?
Add the ones.
Add partial sums.
0.1s 0.01s
If adding results in a single digit in each column, then
sum has been found.
If the sum in any column is a 2-digit number, it is
renamed and part of it is added to the sum in the
column to its left. (Carrying)
Lets try one!
SRB p. 35
TLG P. 87
Part 1
Partial Sum Method with decimals
TLG Page 88
SRB 13
Part 1
Column­Addtion Method
2
2.2 adding whole # and decimals.notebook
Everyday Math
2.2
Math Journal
September 30, 2011
Everyday Math
2.2
Math Journal
Open your journal to page 33
and complete the problems using
partial-sums method.
Open your journal to page 33
and complete the problems using
partial-sums method.
Remember to use the workspace provided.
Remember to use the workspace provided.
TLG Page 88 SRB Page 33
Part 1
TLG Page 88 SRB Page 33
Part 1
Sep 4­3:06 PM
Math Journal
journal 32
Sep 18­7:18 PM
Sep 18­7:20 PM
3