## Mouse Count

In this lesson, children will count sets of mice and add sets of mice together up to 10 and subtract from the set of mice, from 10 down to zero.

### Lesson for:

Toddlers/Preschoolers
(See Step 5: Adapt lesson for toddlers or preschoolers.)

### Content Area:

Algebra
Numbers and Operations

### Learning Goals:

This lesson will help toddlers and preschoolers meet the following educational standards:

• Understand meanings of operations and how they relate to one another
• Compute fluently and make reasonable estimates
• Use mathematical models to represent and understand quantitative relationships

### Learning Targets:

After this lesson, toddlers and preschoolers should be more proficient at:

• Understanding various meanings of addition and subtraction of whole numbers and the relationship between the two operations
• Understanding the effects of adding and subtracting whole numbers
• Developing and using strategies for whole-number computations, with a focus on addition and subtraction
• Developing fluency with basic number combinations for addition and subtraction
• Modeling situations that involve the addition and subtraction of whole numbers, using objects, pictures and symbols

## Mouse Count

### Lesson plan for toddlers/preschoolers

#### Step 1: Gather materials.

• The book, Mouse Count by Ellen Stoll Walsh
• Ten mice cutouts for each child and teacher (You can also use other manipulatives and have them represent mice. You should have three mice of one color, three mice of a different color and four mice of another color.)
• Cutouts of a jar for each child (or actual jars)
• Snake sock puppet or a rubber snake.
• Gallon-sized plastic bags with zipper tops (enough for each child and the teacher)

Note: Small parts pose a choking hazard and are not appropriate for children age five or under. Be sure to choose lesson materials that meet safety requirements.

#### Step 2: Introduce activity.

1. Explain that today the children will be counting mice.
2. Prepare 10 mouse cutouts for each child (three brown, three tan and four white) and the teacher and a jar cutout for each child and the teacher. Place the 10 mice and the jar in the plastic bag for each child.
3. Display your mice and jar in a place where the children can see them. Make sure that the mice are arranged in three groups by their colors (brown, tan and white).

#### Step 3: Engage children in lesson activities.

1. Read the book, Mouse Count, to the children.
2. Using the snake puppet, add the appropriate number of mice to the jar at the appropriate places in the story. When the snake first encounters the three sleeping mice and counts and puts each mouse into the jar, count along with the snake as you drop each of the three mice into the jar. Use the three mice of the same color.
3. Before you read on, say: “There are three mice in the jar, I wonder how many more mice the snake will add to the jar?” Because of the color groupings of the mice, the children may be able to predict correctly the next number of mice to be added to the jar.
4. When you get to the part in the book where the snake finds four mice, say: “There are three mice in the jar. Now the snake is adding four more mice to the jar. Let’s count and see how many three mice plus four mice makes. One, two, three, four, five, six, seven. Seven mice in the jar.”
5. Then, later in the story, say: “There are seven mice in the jar. Now, the snake adds three more mice to the jar. Let’s count and see how many are in there now.” (Count to 10.) “There are 10 mice in the jar.”
6. When you get to the part of the book where the mice rock and tip the jar over, do the same with your jar full of mice. In the book, all of the mice tumble out but, when you tip your jar over, only have some of the mice fall out.
7. Depending on how many mice fall out, ask: “There were 10 mice in the jar. Four mice fell out of the jar. How many mice are left in the jar?” Have the children count the remaining mice in the jar. Say: “Six mice remain in the jar. So, we can say, 10 mice take away four mice, leaves six mice.” Repeat this several times, covering all of the combinations of 10.
8. Tell the children that now they are going to help you mouse count. Give each child the plastic bag with the cutout of the jar and the 10 mice.
9. Re-read the story, pausing each time mice are added to the jar so that the children can add the correct number of mice to their jar. Count the number of mice together as they add mice to their jars.
10.  After each deposit of mice, ask the children to count the mice in their jars to make sure that they are accurately counting the number of mice. Ask the questions that help to reinforce their counting and problem solving. “If we have three mice in our jars and we add four mice to our jars, how many is three mice and four mice?” (Seven mice.) “That’s right. We have seven mice in our jars.”
11.  Once the children’s jars are filled with all 10 mice, tip over the jar and start taking away mice from the jar. Ask: “We have 10 mice in our jars and six mice spilled out. How many mice do we have left in our jars? (Four mice.) “Yes, that’s correct, four mice are left in the jar.”
12.  Continue until there are no more mice left in the jar.

• Throughout the day, create opportunities for the children to count sets and add and/or subtract objects from the set. An easy way to do this is with the daily attendance. Say: “There are four girls and five boys here today. If we add the girls and the boys together, how many children are there in school today?”
• For a subtraction opportunity, say: “There are 10 children standing in line. What if the children with blonde hair sit down? How many children are left standing in line?”

#### Step 4: Vocabulary.

• Add: Increase in amount or number (e.g.,”Now the snake adds three more mice to the jar.”)
• How many: The total or sum (e.g.,”Let’s count and see how many mice are in the jar now.”)
• Subtract: Take one quantity away from another (e.g.,“We have 10 mice in the jar. We subtract 5 mice from the jar. How many mice are left in the jar?”)
• Take Away: To remove something (e.g.,“If we have seven mice in a jar and we take away three mice, how many mice will be left in the jar?”)
• Count: To identify the amount of something by number (e.g.,”Let’s count the number of mice together as we add mice to the jar: 1, 2, 3.” Point to each object while saying “1-2-3.”)

#### Step 5: Adapt lesson for toddlers or preschoolers.

###### Toddlers may:
• Still be working with one-to-one correspondence and counting
• Still be working on combinations of 10 and adding single-digit numbers
###### Child care providers may:
• Assist the children in counting aloud as they add the mice to their bags
• Reinforce numbers added by counting aloud and modeling the adding of the mice to the jar
###### Preschoolers may:
• Have solidified their base-ten knowledge and easily work with combinations of 10
###### Child care providers may:
• Increase the number of mice that the children add and subtract from the jar
• Throughout the day, create opportunities for the children to count sets and add and/or subtract objects from the set (An easy way to do this is with the daily attendance: “There are four girls and five boys here today. If we add the girls and the boys together, how many children are there in school today?”

### Suggested Books

• Mouse Count by Ellen Stohl Walsh (New York: HMH Books for Young Readers, 1995)

### Outdoor Connections

• While waiting to go outdoors, create scenarios where children will have opportunities to count sets and combine (add) sets together or remove (subtract) objects from a set.
• Using any objects found outside, have the children work with predetermined sets of objects (10 leaves of different colors, 10 kinds of playground equipment, 10 clothing items needed when the weather gets colder, etc.)