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5th Grade Module 2 – Lesson 23
Lesson 23: I can divide three and four digit dividends by two digit divisors
resulting in two and three digit quotients, reason about the decomposition of successive
remainders in each place value.
5th Grade Module 2 – Lesson 23
Divide Decimals
6 tens ÷ 3 =
Say the division
sentence in unit form.
Six tens divided by three equals
two tens.
5th Grade Module 2 – Lesson 23
Divide Decimals
6 tenths ÷ 3 =
Say the division
sentence in unit form.
Six tenths divided by three
equals two tenths
5th Grade Module 2 – Lesson 23
Divide Decimals
6 hundredths ÷ 3 =
Say the division
sentence in unit form.
Six hundredths divided by
three equals two
hundredths.
5th Grade Module 2 – Lesson 23
Divide Decimals
9 thousandths ÷ 3 =
Say the division
sentence in unit form.
Nine thousandths
divided by three equals three thousandths.
5th Grade Module 2 – Lesson 23
Divide Decimals
9 tenths ÷ 3 =
Say the division
sentence in unit form.
Nine tenths divided by three
equals three tenths.
5th Grade Module 2 – Lesson 23
0.1Say the number
as a decimal.
One tenth
Rename Tenths and Hundredths
5th Grade Module 2 – Lesson 23
0.2Say the number
as a decimal.
two tenths
Rename Tenths and Hundredths
5th Grade Module 2 – Lesson 23
0.3Say the number
as a decimal.
three tenths
Rename Tenths and Hundredths
5th Grade Module 2 – Lesson 23
0.8Say the number
as a decimal.
eight tenths
Rename Tenths and Hundredths
5th Grade Module 2 – Lesson 23
0.9Say the number
as a decimal.
nine tenths
Rename Tenths and Hundredths
5th Grade Module 2 – Lesson 23
10 tenths = 11tenths =19 tenths=20 tenths =30 tenths =80 tenths =90 tenths =100 tenths =200 tenths =
Write the number.
Rename Tenths and Hundredths
5th Grade Module 2 – Lesson 23
1hundredth = 2 hundredths =3 hundredths=8 hundredths =9 hundredths =100 hundredths =200 hundredths =900 hundredths =1000 hundredths =
Write the number.
Rename Tenths and Hundredths
5th Grade Module 2 – Lesson 23
Divide by Two Digit Numbers
650 ÷ 16÷ 20 60
0 30
Estimate Standard Algorithm
650 ÷ 16
650164
-64
R10
10
0
- 0 10
5th Grade Module 2 – Lesson 23
Divide by Two Digit Numbers
740 ÷ 32÷ 30 72
0 24
Estimate Standard Algorithm
740 ÷ 32
74032 2
-640100
R4
- 964
3
5th Grade Module 2 – Lesson 23
Divide by Two Digit Numbers
890 ÷ 27÷ 30 90
0 30
Estimate Standard Algorithm
890 ÷ 27
890273
-81
R26
80
2
-54 26
5th Grade Module 2 – Lesson 23
Application Problem
The rectangular room measures 224 square feet. One side of the room is 14
feet long. What is the perimeter of the room?
Solution on next slide…
Hint…This is a two-step problem.
5th Grade Module 2 – Lesson 23
Solution
14 16224
-14 84224 ft2
-84 0
14
?(16 x 2) + (14 x 2) =
32 + 28 = 60 ft perimeter
5th Grade Module 2 – Lesson 23
Concept Development
6,247 ÷ 29 Let’s first use rounding to find an estimated quotient!
6247 ÷ 17≈ 6000 ÷ 30 ≈ 200
Standard Algorithm
6247
29Can we divide 6 thousands
by 29?Not without regrouping!
So let’s work with 62 hundreds!Divide 62 hundreds by 29. We can use estimation to help us find the closest
quotient.Think…
60 hundreds ÷ 30 = 2 hundreds
2
58
So our quotient is about 2 hundred. Let’s record a 2
in the hundreds place.
On your whiteboard solve2 hundred x 29 =
We will record it under the dividend
How many hundreds are remaining?62 hundred – 58 hundred
4 hundredLet’s record that on the standard
algorithm
-___ 4
5th Grade Module 2 – Lesson 23
Concept Development
6,247 ÷ 29
Standard Algorithm
6247
292
58-___ 4
Let’s decompose (regroup) the 4 hundreds into 40 tens plus the 4 tens
still left in the dividend.
That will give us 44 tens
We can bring down the 4 and write it next to the 4 in the hundreds place.
4
Now we must divide 44 tens by 29.
Estimate 44 ÷ 29 on your white board
The best estimation to use is30 tens ÷ 20 = 1 ten
So we can put a 1 in the tens place in the quotient.
1
What is 1 ten X 29 =
29
How much is still remaining?44 – 29 = ___
-___ 15
Can we divide again or must we decompose?
We can’t divide again because the reminder is less
than the divisor.We need to decompose 15 tens into 150 ones, plus the
7 ones in our whole, to make 157 ones.
7
Now we have 157 ones divided by 29.
Estimate 157 ÷ 29
150 ÷ 30 = ___5Let’s finish up the problem by using 5.
Find 5 x 29 then find the remainder.
145
5
145-___ 12
What does the 12 remaining mean?
Check the answer on your white board.
5th Grade Module 2 – Lesson 23
Let’s do this one together. First, estimate the quotient.
Solution (use ink tools):
4,289 ÷ 52
5th Grade Module 2 – Lesson 23
Work with your partner to solve for the quotient. Estimate, solve, and check.
Solution (use ink tools or display student work):
6,649 ÷ 63
5th Grade Module 2 – Lesson 23
Solve this problem independentlyEstimate, solve, and check.
Solution (use ink tools or display student work):
3,164 ÷ 45
5th Grade Module 2 – Lesson 23
Get Ready to Complete theProblem Set on Your Own!
Complete Pages 2.F.55 & 2.F.56You will have 15-20 minutes to work.
Try your Best!
5th Grade Module 2 – Lesson 23
LET’S DEBRIEF• What pattern did you notice between 1(e) and 1(f)? Since the
quotient was 70 with remainder of 14 for both problems, does that mean the two division expressions are equal? Does the remainder of 14 represent the same thing?
• When dividing did your estimate need adjusting at times? When? What did you do in order to continue dividing?
• Compare your quotients in Problem 1. What did you notice in Problem 1 (a, b, and c)? Will a four-digit total divided by a two-digit divisor always result in a three-digit quotient? How does the relationship between the divisor and the whole impact the number of digits in the quotient?
5th Grade Module 2 – Lesson 23
EXITTICKETPage 2.F.57
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