Adding Tenths and Hundredths
Lesson 5-5
DATETIME
Sample equations:
Use what you know about equivalent fractions to add. Write an equation to show your work.
SRB
166–168
1 5 tenths + 27 hundredths
Equation (in words):
50 hundredths + 27 hundredths = 77 hundredths
2 16 hundredths + 7 tenths
Equation (in words):
16 hundredths + 70 hundredths = 86 hundredths
3 ​ _
   ​ + ​ _  ​ 
100
10
8
6
8
60
68
___
___
___
​  100
  ​ + ​  100  ​ = ​  100  ​
 
Equation:
42
9
4 ​ _  ​ + _
​  10  ​ 
100
90
132
32
42
___
___
___
​ 100
  ​ + ​  100  ​ = ​  100 
 
​,  or 1​ ___
 
100  ​
Equation:
3
50
5 ​ _  ​ + ​ _  ​ 
10
100
30
50
80
3
5
8
___
___
___
__
__
__
​  100
  ​ + ​  100  ​ = ​  100  ​ or ​  10  ​   + ​  10  ​   = ​  10  ​
 
Equation:
5
20
1
6 ​ _  ​ + _
​  100  ​ + ​ _
  
​ +
10
10
Equation:
7 ​ _
  ​ 
100
55
10
5
200
55
70
7
___
___
___
___
__
​ 100
  ​ + ​  100
  ​ + ​  100 
 
​ + ___
​  100
  ​ = 100
​  270  ​,  2​ ___
 
 
,
​
 
or
2​ 
​ 
100
10  
35
2
1​ _
  ​ + 6​ _  ​ 
10
100
Equation:
20
35
55
___
___
1​ ___
 
 
​
 
+
6​ 
 
 
​
 
=
7​ 
 
100
100
100  ​
Try This
8 Ali shaded 0.4 of a hundreds grid. Tarun shaded 0.32 of the same grid. How much of the
grid did they shade in all?
Number model with unknown:
Answer:
164 0.72 of the grid
0.4 + 0.32 = g
Explain how you got your answer.
Sample answer: I can rename 4 tenths + 32
hundredths as 40 hundredths + 32 hundredths.
40 hundredths + 32 hundredths =
72 hundredths, or 0.72.
4.NF.1, 4.NF.5, 4.NF.6, SMP2