CCSS Activity 26 with Student Master
In Unit 12, Lesson 7, Solving Problems with Pattern Blocks, students use pattern blocks to solve word problems
involving addition of fractions. Extend the lesson to include addition of mixed numbers. After students have
completed the lesson, introduce the idea of adding mixed numbers by renaming each mixed number as an equivalent
fraction. Write the following problem on the board: 3 __
​ 34 ​+ 2 __
​ 14 ​. Explain that one way to add mixed numbers is to
rename them as fractions. Then, the fractions can be added. Begin by modeling 3 __
​ 14 ​by drawing the following on the
board and ask:
• If the circle is one whole, what mixed number does this picture show? (3 __
​ 34 ​)
Draw lines to divide each circle into fourths and label each part with the fraction __
​ 14 ​.
Ask:
• How can we rename this mixed number as an equivalent fraction? (Count all of the fourths shown: Each
15
circle has 4 fourths, so there are __
​ 44 ​+ __
​ 44 ​+ ​ __44 ​+ ​ __34 ​= __
​ 15
  ​. So ​ __  ​is the same as 3 __
​ 34 ​.)
4
4
Ask a volunteer to rename 2 __
​ 14 ​as a fraction (​ __44 ​+ __
​ 44 ​+ __
​ 14 ​= __
​ 94 ​).
( 
)
9 24
Then, ask students to solve the fraction addition problem: __
​ 15
  ​+ ​ __ ​​ __
​    ​; 24 ÷ 4 = 6, so the answer is 6  ​.
4
4 4
Do a few more examples with the class. Encourage students to use pattern blocks, draw pictures, or rename mixed
numbers as equivalent fractions to solve the problems. Examples: 5 __
​ 13 ​+ 2 __
​ 13 ​; 4 __
​ 16 ​+ 3 __
​ 46 ​; 2 __
​ 56 ​+ 3 __
​ 36 ​
Then distribute CCSS Activity 26 Student Master, Adding More Mixed Numbers.
Common Core State Standard 4.NF.3c Add and subtract mixed numbers with like denominators, e.g., by replacing each mixed number with
an equivalent fraction, and/or by using properties of operations and the relationship between addition and subtraction.
48 MTB • Grade 4 • CCSS • Teacher Notes
CCSS Activity 26 with Student Master, Part 2
Unit 12, Lesson 7 also provides an opportunity for students to practice adding fractions with 10 and 100 in the
denominator. The homework assignment on Student Guide, page 352 includes problems requiring students to write
equivalent fractions. As you go over the homework, include more examples of renaming tenths as hundredths, and
hundredths as tenths. Have students show their equivalencies using base-ten pieces or a tenths helper chart.
Then have students complete CCSS Activity 26 Student Master 2, Adding Tenths and Hundredths 2, to give them
practice using these equivalencies to add fractions with 10 and 100 in the denominator.
Common Core State Standard 4.NF.5 Express a fraction with denominator 10 as an equivalent fraction with denominator 100, and use this
3
30
3
34
4   ​ = ___
technique to add two fractions with respective denominators 10 and 100. For example, express __
​ 10
  ​ as ___
​ 100
  ​,  and add __
​ 10
  ​ + ___
​ 100
​ 100
   
​.
MTB • Grade 4 • CCSS • Teacher Notes 49
CCSS Activity 26 Student Master
Name
Date
Adding More Mixed Numbers
Add. Use pattern blocks, draw pictures, or rename mixed numbers as equivalent
fractions to help you.
1. 4 __
​ 3 ​+ 2 __
​ 1 ​=
4
4
2. 2 __
​ 4 ​+ 3 __
​ 1 ​=
6
6
3. 3 __
​ 2 ​+ 4 __
​ 2 ​=
3
3
4. 1 __
​ 1 ​+ 2 __
​ 3 ​=
8
8
5. 2 __
​ 35 ​+ 4 __
​ 45 ​=
6. 5 __
​ 1 ​+ 8 __
​ 1 ​=
2
2
50 MTB • Grade 4 • CCSS • Teacher Notes
CCSS Activity 26 Student Master 2
Name
Date
Adding Tenths and Hundredths 2
Add. Find equivalent fractions to help you.
1. ___
​ 8  ​ + ___
​  2   ​ =
10
100
2. ___
​  6   ​ + ___
​ 3  ​ =
100
10
3. ___
​ 9  ​ + ___
​  7   ​ =
10
100
4. ___
​  8   ​ + ___
​ 2  ​ =
100
10
5. ___
​ 5  ​ + ___
​  4   ​ =
10
100
6. ___
​  5   ​ + ___
​ 8  ​ =
100
10
MTB • Grade 4 • CCSS • Teacher Notes 51