Download Subtract Whole Numbers

Subtract Whole Numbers
Unit 2 Lesson 5
Objectives
• Explain and apply standard step-by-step
approaches for subtraction.
• Use an inverse relationship to simplify a
computation or check a result.
• Determine a missing number in an equation or an
inequality.
• Determine the sum or difference of two whole
numbers.
• Use the inverse relationship between addition
and subtraction to solve problems.
Inverse operations are opposite operations
because they undo each other.
Example:
15 + 8 = 23
23- 8 = 15
*Think about it: how are these two problems
related?
Use the inverse operation to find the
answer!
Use the inverse operation to find the
answer!
Now, let’s look at 3
different ways to solve a
subtraction problem!
Method 1: Addition to Subtract
Lesser Number
5,523
- 2,357
Greater Number
Begin with the lesser number and
add up to get to the greater
number.
Method 1: Addition to Subtract
5,523
- 2,357
We’ll start with the ones place. Look at the
lesser number and see how many ones we
need to add on.
2,357+3=2,360
Method 1: Addition to Subtract
2,357+3=2,360
+ 40
2,400
Target Number
5,523
-2,357
Next we’ll look at the tens place. We
need to figure out what to add to 2,360
to get to the next number in the
hundreds place.
Method 1: Addition to Subtract
2,357+3=2,360
+ 40
2,400
+ 600
3,000
Target Number
5,523
-2,357
Now we’ll move to the hundreds place.
I need to figure out how many hundreds
to add to get to the next thousand.
Method 1: Addition to Subtract
2,357+3=2,360
+ 40
2,400
+ 600
3,000
+2,000
5,000
Target Number
5,523
-2,357
Then we’ll move to the thousands place. Our
target number is 5,523, so I need to add
2,000 to get to 5,000.
Method 1: Addition to Subtract
2,357+3=2,360
+ 40
2,400
+ 600
3,000
+2,000
5,000
+ 523
5,523
Target Number
5,523
-2,357
Next I need to add hundreds, tens and ones
until I get to 5,523. I need to add 523 to
5,000.
Method 1: Addition to Subtract
2,357+3=2,360
+ 40
2,400
+ 600
3,000
+2,000
5,000
+ 523
5,523
3
40
600
2,000
+ 523
3,166
Now I find the sums of everything I
added to find how much I counted up.
Method 2: Place Value
First, we need to look at the
expanded form of the number
with the least value.
2,000 + 300 + 50 + 7
Method 2: Place Value
2,000 + 300 + 50 + 7
Method 3: Standard Algorithm
Method 3: Standard Algorithm
First, look at the ones place numbers. If the
number on top is smaller than the bottom
number, I must regroup before I subtract.
Method 3: Standard Algorithm
Next, look at the tens place numbers. If the
number on top is smaller than the bottom
number, I must regroup again before
subtracting.
Method 3: Standard Algorithm
Now, look at the hundreds place numbers. If
the number on top is smaller than the
bottom number, I must regroup again before
subtracting.
Method 3: Standard Algorithm
Now, subtract the thousands. So, our
answer is 3,166.
Let’s Try It!
9,076
- 4,652
Let’s Try It!
45,893
- 12,945
There are 28,708 fans at the first basketball
game of the season. There are 8,993 fans at
the second basketball game of the season.
How many more fans would need to attend
the second basketball game to have the same
number of fans as the first game?
Find the difference between 6,345 and 451.
Which is the first step when subtracting 597
from 9,246?
Camille subtracted 3,256 from 6,000 and got
9,256. Which correctly explains the mistake
that Camille made and gives the correct
answer?
Simone knows that 67 + 34 = 101.
How will this help her solve the problem 101 – 34?
Write a number sentence that will
correctly solve this problem:
A stadium holds 71,030 people. Thirty
minutes before the game started there were
34,761 in the stadium. How many more
people would have to come so that all the
seats were filled?
Margo was asked to put numbers in the boxes
to make this equation correct.
4, 3 – 2,749 = 1,489
Margo doesn't want to use the 'guess and
check' strategy. Which strategy could Margo
use?
Subtract:
8,743 – 689 =
Subtract:
6,046
– 39