Transcript Slide 1
Whole Numbers
Adding & Subtracting Group #1 Copyright © Ed2Net Learning, Inc.
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Warm-up
What is the next number in the pattern?
3,7,11,15, 19 16 - 4 + 2 - 10 = 4 Insert <, >, or = 22 – 7 = 10 + 5 6 + 23 > 33 -5 Copyright © Ed2Net Learning, Inc.
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Notation and Place Value
Place Value
helps you better understand the Whole Numbers (0,1,2,3,4,5,6,7,8,9..) To determine the
value
of each
digit
number, we need to look at its number.
place
in the in the Copyright © Ed2Net Learning, Inc.
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Notation and Place Value
Here is the place value chart to the
billions
place.
, , Fill in the number 34,567,129 , Which number is in the ten thousands place? 6 Notice the commas separating every three digit Copyright © Ed2Net Learning, Inc.
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Let’s look at the number 37,264,908
Which number is in the
millions
place? 7 Which number is in the
hundreds
place? 9 Which number is in the
tens millions
place? 3 Which number is in the
thousands
place? 4 Copyright © Ed2Net Learning, Inc.
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Different ways to write numbers
Standard Form: 423 Expanded Form: 400 + 20 + 3 Word Form: Four hundred twenty three Copyright © Ed2Net Learning, Inc.
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Let’s look at the number 1,734
This number is written in standard form Can you write this number for me in
word form
? One thousand seven hundreds thirty four Can you write this number for me in
expanded form
? 1000 + 700 + 30 + 4 Copyright © Ed2Net Learning, Inc.
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Comparing & Ordering
We compare numbers using
Place Value
When we compare two numbers, we start from left to right. It is necessary to find the first place where the digits are different.
Step 1: Begin at the greatest place. Find where the digits are different.
Step 2: Compare the digits that are different. Write > or <.
Example: Compare 3,567 and 3,576 Step 1: 3,5 6 7 Step 2: 3,5 7 6 3,5 6 7 3,5 7 6 Same Different 7 hundreds > 6 hundreds So, 3,576 > 3,567 Copyright © Ed2Net Learning, Inc.
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Comparing & Ordering
Many times there are more than 2 numbers that we want to compare. We can
order
the numbers by placing them in an order from
least to greatest
or
greatest to least
We must compare two at a time.
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Comparing & Ordering
Let’s order these numbers from
Least to Greatest
3,670 3,607 3,076 3,706
Remember to start with 2 at a time
Be careful when reading the instructions! Are they asking for the smallest or the biggest? Are they asking you to order the numbers from least to greatest or greatest to least?
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Estimate
When we
estimate
, we find a number that is close to the exact number.
Let us estimate the sum of 198 + 104 198 is close to 200 104 is close to 100 300 is an
estimate
of the sum Copyright © Ed2Net Learning, Inc.
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Try This!
1.
Estimate each sum: 93 + 54 = 90 + 50 = 140 2.
487 + 519 = 500 + 500 = 1,000 3.
26 + 197 = 30 + 200 = 230 Copyright © Ed2Net Learning, Inc.
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Rounding
Rounding
is one of the ways we estimate We can use place value to round Let’s round 2,345 to the nearest thousands place.
Step 1: We need to underline the thousands place. 2,345 Copyright © Ed2Net Learning, Inc.
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Rounding
Step 2: We need to look at the digit just to the right of the underlined digit. 2,345 If that digit is 5 or more, we increase the underlined digit by 1.
If that digit is 4 or less, we do not change the underlined digit.
Since this digit is 4, we do not change the the digit 2 Copyright © Ed2Net Learning, Inc.
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Rounding
Step 3: We change all the digits to the right of the underline digit to 0.
2,345 rounds to 2,000 Copyright © Ed2Net Learning, Inc.
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Try This!
1.
Round 2,456 to the nearest tens place. 2,460 2.
Round 836 to the nearest hundreds place. 800 3.
Round 34,185 to the nearest thousands place. 34,000 Copyright © Ed2Net Learning, Inc.
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Addition of Multi-Digit Numbers
There are several properties of addition
Commutative Property
We can change the order and the sum stays the same.
4 + 6 = 10 6 + 4 = 10
Associative Property
We can change the grouping and the sum stays the same.
2 + (3 + 8) = 13 (2 + 3) + 8 = 13
Identity Property
We can add zero and the sum stays the same.
7 + 0 = 7 Copyright © Ed2Net Learning, Inc.
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Try This!
Use the commutative property of addition to complete this problem 34 + 56 = 56 + 34 Use the associative property of addition to complete this problem 47 + (94 + 25) = (47 + 94) + 25 Copyright © Ed2Net Learning, Inc.
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Where do you put the parentheses ?
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Try This!
Use the identity property of addition to complete the problem.
7,984 + 0 = 7,984 Copyright © Ed2Net Learning, Inc.
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Addition of Multi-Digit Numbers
Step 1: We add numbers together by first lining up the digits Step 2: Then we need to determine if we must regroup.
1 197 +35 232 7 + 5 = 12 so we must regroup 12 ones as 1 ten and 2 ones Copyright © Ed2Net Learning, Inc.
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Try This!
673 + 87 760 759 +682 1,441 Copyright © Ed2Net Learning, Inc.
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Subtraction of Multi-Digit Numbers
13 – 0 =13 If we subtract zero from any number the difference is that number 57 – 57 = 0 If we subtract a number from itself, the difference is 0 Copyright © Ed2Net Learning, Inc.
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Subtraction
Subtraction is similar to addition We need to line up digits Often we need to regroup Copyright © Ed2Net Learning, Inc.
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Subtraction
Remember that subtraction begins from the top number and starts in the ones place.
27 - 5 It’s 7 minus 5 If the problem is written horizontally 156 – 78 The top number is the number to the left of the subtraction sign Copyright © Ed2Net Learning, Inc.
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Subtraction
We begin by subtracting the ones.
If the top number is smaller than the bottom number, we have to regroup.
23 -17 1 23 13 - 17 6 Copyright © Ed2Net Learning, Inc.
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Try This!
532 -278 254 3,254 - 367 2,887 Copyright © Ed2Net Learning, Inc.
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Assessment
1.
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3.
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6.
7.
Write 23,654 in word form. Twenty three thousands, six hundreds fifty four Write the place value of the underlined digit; 546,981 500,000 Which number is smaller, 67,987,024 or 67,987,042 ? 67,987,024 What does the word “estimate” mean? Can you give me an example? 99 When we estimate we find a number that is close to the exact number; 100 is an estimate of Round 5,632 to the nearest hundreds place. 5,600 Round 1,287,583 to the nearest ten thousands place. 1,290,000 Order this set of data from least to greatest: 134 143 157 107 140 107, 134, 140, 143, 157 Copyright © Ed2Net Learning, Inc.
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Assessment
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11.
Use the commutative property of addition to complete the problem 134 + 58 = 58 + 134 Use the associative property of addition to complete the problem 148 + (92 + 302) = (148 + 92) + 302 Find the sum 1,473 + 698 = 2,171 Find the difference 23,064 – 12,635 = 10,429 The town where Henry lives has a population of 3,782 people. During the last two years, 319 people have moved into town. About how many people lived in Henry’s town two years ago? The number 3,782 rounded to the nearest hundred is 3,800. The number 319 rounded to the nearest hundred is 300. The number sentence 3,800 – 300 = 3,500 shows about how many people lived in Henry’s town two years ago. The population of Henry’s town two years ago was about 3,500 people.
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You did a great job today!
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