### EL Support Lesson

# Building in Base-Ten

#### Objectives

##### Academic

Students will be able to name and compose two-digit numbers with base-ten blocks.

##### Language

Students will be able to describe the value of digits in the tens and ones places, and compose and decompose two-digit numbers with manipulatives, word banks, and partner support.

#### Introduction

*(5 minutes)*

- Gather students on the rug and ask them to show you a number of fingers less than 10.
- Ask students whether or not it is possible for just one student to show 44 fingers.
- Work together as a class to show 44 fingers. Let students figure out that four students should stand at the front of the class, each showing 10 fingers, with a fifth student showing four fingers.
- Think aloud, "I see four sets of 10 fingers, and four extra fingers. Four sets of 10, plus four, is 44." Point to the raised fingers as you say, "Let's count by tens first. Ten, 20, 30, 40, 41, 42, 43, 44."
- Model showing and counting a few other two-digit numbers as a class.

#### Explicit Instruction/Teacher modeling

*(5 minutes)*

- Instruct students to show you all 10 fingers, and then clasp them together. Tell them they have made a
**group**of 10. - Tell students to move their clasped fingers forward towards you as the class counts chorally by multiples of 10.
- Tape a base-ten rod on the board, and label it
**"ten."** - Tape a base-ten cube on the board, and label it
**"one."**Line up 10 cubes next to the rod so that students can see that the amounts are equivalent. - Show students an arrangement of some base-ten blocks that includes tens and ones on the document camera or on the rug.
- Display the sentence frame, "
**____**tens and**____**ones:**____**." - Model calculating the total number of blocks by saying, "Four tens and four ones: 44." Students repeat after you as you point to the blocks.
- Add a tens rod to the blocks. Explain that when you add 10, the amount of blocks is greater. The total amount is 10
**more.** - Show the students that by removing a tens rod, the total number is 10
**less**. - Instruct students to work with a partner. As you add and remove tens rods, Partner A says the number of tens and ones. Partner B says the standard name of the number.
- Continue the procedure as you add and remove tens and ones cubes.
- Place the blocks in various arrangements as you add and subtract ones and tens. For example, place the ones blocks on the left, or mix ones blocks together with tens blocks to help students focus on the quantities rather than the position of the blocks.
- As students name the numbers, record the numeral, standard name, and base-ten name on the board for reference.

#### Guided Practice

*(10 minutes)*

- Distribute base-ten blocks to students, and instruct them to build the number that you say.
- Call out a number between 1-99. Students will build the number with the base-ten blocks.
- The partners will switch roles. Partner A will say the standard name and Partner B will say the base- ten name, "
**____**tens and**____**ones." - Instruct students to add and subtract ones and tens, naming each number with both the standard and base-ten name.

#### Group work time

*(10 minutes)*

- Tell the story problem, "Jenni read 12 books for the read-a-thon. Joshua read one less book than Jenni. How many books did Joshua read?"
- Model solving the problem first with base-ten blocks. Then, write an equation to go with the base-ten model.
- Tell the students the story problem, "Jenni has 20 pieces of candy. Joshua has 10 more pieces of candy than Jenni. How many pieces of candy does Joshua have?"
- Instruct students to solve the problem with base-ten blocks. Then, tell them to write an equation to represent the problem.
- Direct students to write similar story problems involving one more, 10 more, one less, or 10 less with their partners.
- Tell students to solve their own word problem first, and then exchange problems with another partnership. Encourage students to notice how the other partnership solved their problem.

#### Additional EL adaptations

**Beginning**

- Allow students to write story problems using home language (L1).
- Work with students in a teacher-led small group to build numbers with base-ten blocks. Support students to say both the base-ten and standard number names.

**Advanced**

- Teach students to write two-digit numbers with expanded notation, for example
**40 + 4 = 44.**

#### Assessment

*(5 minutes)*

- Circulate and notice whether students are able to count tens and ones blocks accurately, and name the numbers with the base-ten and standard names.
- Observe that students are able to work with a partner to write a story problem involving 10 more, 10 less, one more, or one less.
- Check that students are able to understand and solve one another's problems accurately using base-ten blocks. If students solve the problems incorrectly, have students explain their thinking before making corrections.
- Note any common errors to address at closing.

#### Review and closing

*(5 minutes)*

- Close the lesson by telling students a few base-ten riddles such as:
- I have three tens and two ones. What number am I?
- I have no tens and four ones. What number am I?
- I have nine tens and no ones. What number am I?
- I am ten more than 55. What number am I?
- I am one less than 72. What number am I?

- Encourage students to explain their thinking as they solve the riddles.