Transcript Let`s Round Number!

MAP2D
Trimester 1
Instructional Strategies
Grade 3
Updated 6/09
1
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Find Place Value to 10,000
Write a number in the place value chart to
find the value of each digit in a number.
thousands
TH
3
3
hundreds
H
0
0
tens
T
5
0
ones
O
1
0
Example:
“What is the
value of the
three in the
number three
thousand fiftyone” ?
Answer: 3000
Chapter 1
Lesson 3
2
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Write Numbers in Different Ways
thousands
hundreds
5
6
tens
ones
4
5
Write the number 5,645 in expanded form.
TH
Chapter 1
Lesson 4
H
T
O
3
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Write Numbers in Different Ways
thousands
hundreds
5
6
tens
4
ones
5
Write the number 5,645 in expanded form.
5
5
6
0
6
4
0
0
4
5
0
0
0
5
5,000 + 600 + 40 + 5
Chapter 1
Lesson 4
4
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Write Numbers in Different Ways
thousands
hundreds
5
6
tens
4
ones
5
Write 5,000 + 600 + 40 + 5 in Standard Form.
Write the expanded form in vertical/working form
5,000
600
40
+
5
5,645
Chapter 1
Lesson 4
5
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Write Numbers in Different Ways
thousands
hundreds
tens
ones
5
6
4
5
Write in 50,000 + 600 + 40 + 5 in Standard Form.
Write the expanded form in vertical/working form
5,000
0,600 Fill in the spaces with zeros.
+
0,040
0,005
5,645 Now you have the standard form.
Chapter 1
Lesson 4
6
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Round Numbers!
Long Beach Lifeguards reported to the Press Telegram
that there were 2,857 people at the beach on Sunday.
Round this to the nearest __________
 Underline the word that comes after “nearest”.
 Underline the digit in the indicated place.
 Circle the digit to the right of the underlined place.
 If the circled digit is 5 or greater, add one to the
underlined place and change all digits to the right to
zeros.
 If the circled digit is 4 or less, keep the underlined
place and change all digits to the right to zeros.
Chapter 2
Lesson 4
7
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Compare Numbers
We can compare numbers using >, < and = signs.
25
30
35
32
25 26 27 28 29 30 31 32 33 34 35
 Line up the numbers vertically
25
30
35
32

Start at the left to compare digits in the greatest place first.
Highlight the digits in the first vertical column where the digits are
different.

Now compare these highlighted digits to compare the value.
25 < 30
Chapter 2
Lesson 1
35 > 32
8
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Order Numbers
We can compare a set of numbers by ordering them
from least to greatest.
7,893 7,080, 7,870

Line up the numbers vertically.
least


7,893
7,080
7,870
7,893 greatest
7,870
middle
Start at the left to compare digits in the greatest place first.
Highlight the digits in the first vertical column where the
digits are different. Continue moving to the next column.
Now compare these highlighted digits to compare the value.
7,080
Chapter 2
Lesson 2
7,870
7,893
9
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Find Patterns
25, 30, 35, __, 45, 50
 Subtract to find the difference between two
“neighbors” in the pattern.
30 – 25 = 5
35 – 30 = 5
Then use this difference ( 5 ) to find the missing
number in the pattern.
45 – 5 = 40
The pattern is 25, 30, 35, 40, 45, 50
Chapter 4
Lesson 7
10
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Solve Algebra Equations !
To solve an equation, both sides of the equal sign need to be the same.
Hint: Think of a balance
17 + 8 =  + 12

25 =  + 12 What is the difference between 25 and 12?
25
- 12
13
25
Chapter 3
Lesson 2
= 13 + 12
11
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Solve for Missing Factors !
9 × d = 20 + 7
Hint: Think
of a balance
To solve an equation, both sides of the equal sign need to be the same.
9 × d = 20 + 7

9×d = 27
Think 9 × what = 27?
Think nine groups of
9 × 3 = 27
what = 27?
9×3 =
Chapter 8
Lesson 2
27
12
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
What is the missing number?
To solve an equation, both sides of the equal sign need to be the same.
Hint: Think of a balance
12 x ( 6 x 3 ) = (3 x __ ) x 12
If we have a 12, 6, and 3 on one side of the equal sign, we need to have a
12, 6, and 3 on the other side. The missing factor then is 6.
12 x ( 6 x 3 ) = (3 x 6 ) x 12
216
=
216
Associative Property of Multiplication: Changing the way in which the
factors are grouped does not change the product.
Chapter 8
Lesson 4
13
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3
Let’s Choose the Operation Symbol
9  5 = 45
 Look at the numbers on the side of the equation with
the missing operation sign.
 If the numbers are smaller than the given answer you
must add or multiply to get the larger answer.
 Ask yourself does 9 + 5 = 45? No
 Ask yourself does 9 x 5 = 45? Yes
 The missing operation symbol is multiplication ( x )
It’s All About
the Facts
(+,-,x,÷)
14
Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 3