## Adding With Base Ten Blocks - Section 2: Teaching The Lesson

# We Can Guess the Number

Lesson 4 of 6

## Objective: SWBAT use bundles of 10 and 100 to answer questions about the value of individual digits in 2 and 3 digit numbers.

#### Warming Up

*10 min*

Students were introduced to the Ten's Partner Rhyme in two previous lessons. To reinforce the rhyme and the ten's partners we start today by chanting the rhyme together and doing a few finger partners such as put up 3 fingers, how many more to make 10?

Today I make this a bit more difficult. Students put up both hands. I call out a number and they put up the number of fingers more that they will need to get to ten. (I call out 2 and they put up 8 fingers.) This is a silent activity, but one where I can informally assess students to see if they are grasping the concept. I record any student difficulties on my clipboard.

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#### Teaching The Lesson

*35 min*

Today I break the class into groups based on their current understanding of the value of digits, (based on my informal observations and notes). Some students are ready to add using bundles of 10s and left over ones. Others need to continue to review what a bundle of ten means. I explain to students that there will be several different activities going on today. They may not get a chance to do every activity.

I explain that all students will meet with me during one of their blocks, and follow the directions they find at the centers where I am not present. They will have 10 minutes at each center. A parent volunteer would be helpful at this point but I do not have one today. The objective for today is for students to model tens and ones (and hundreds for those who are ready) using a variety of different materials and processes. (MP4)

Centers I will run:

1. Students will take colored chips and put them on Ten's Frames as I dictate start with 3 chips. How many more do you need to make a bundle of ten. This will reinforce partners of ten. They will then count how many ten's frames they have and count by tens to record the number. We will discuss how the digit in the tens place tells us how many frames we have filled.

2. For students who show an understanding of partners of ten, students count out bundles of 10 straws and band them together. They will then take less than 10 and leave them unbundled. They will show their number to a partner who will write the number on an erasable board.

3. For students who show an understanding of digits, they will be given 2 numbers to make using base ten blocks. They will add the two numbers together and get an answer. They will explain what they did to get the final answer.

Centers students will visit independently:

1. Students will work in partners. One partner will be the timer and count back from 30 to 0 while the other partner builds a tower with hundreds, tens and ones base ten blocks. At the end of the 30 second count, the partner will count how many hundreds and write the number, then the number of tens, and then the number of ones. He/she will read the total aloud.

2. Students will work in partners. One partner will spread out the cards, numerals 0 - 9, on the table. The second partner will try to match all the partners of ten while the first partner times with a second hand, or by counting slowly. The student will record his/her time and then the partners will switch roles. They will repeat this 5 times each.

At the end of the 5 trials, the students will use the remainder of the number deck, draw 2 cards at a time to make a two digit number. The student with the higher number will take the cards. The student with the most cards wins the game.

At the end of the centers students will return to their desks to record in their journals what they know about partners of 10.

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- UNIT 1: What and Where is Math?
- UNIT 2: Adding and Subtracting the Basics
- UNIT 3: Sensible Numbers
- UNIT 4: Sensible Numbers
- UNIT 5: Everything In Its Place
- UNIT 6: Everything in Its Place
- UNIT 7: Place Value
- UNIT 8: Numbers Have Patterns
- UNIT 9: Fractions
- UNIT 10: Money
- UNIT 11: The Numbers Are Getting Bigger
- UNIT 12: More Complex Numbers and Operations
- UNIT 13: Area, Perimeter and More Measurement
- UNIT 14: Length
- UNIT 15: Geometry
- UNIT 16: Getting Ready to Multiply
- UNIT 17: Getting Better at Addition and Subtraction
- UNIT 18: Strategies That Work