Objective:

Students will use physical objects to model and solve word problems involving addition and subtraction within 20, developing their understanding of how to decompose numbers into parts and how to represent unknowns in different positions. Through this activity, students will learn to break down mathematical problems step-by-step, fostering computational thinking.

Materials Needed:

• Counters or small objects (e.g., cubes, beads, or buttons)

• Large paper or whiteboards for drawing equations and solutions

• Number cards or symbols to represent unknowns

Steps:

• Introduction:

  • Begin by discussing everyday situations where addition and subtraction are used, such as combining toys or sharing snacks. 

  • Ask, "If you had 5 cookies and gave 2 to a friend, how many would you have left?" 

  • Write the equation on the board and solve it together, introducing students to the idea of representing unknowns with symbols.

• Group Activity:

  • Divide students into small groups. 

  • Give each group a set of counters and a word problem card (e.g., "You have 8 apples and buy 5 more. How many apples do you have now?"). 

  • Have them use the counters to solve the problem, laying out the physical objects and writing the corresponding equation on paper or a whiteboard. 

  • As they work through the problems, encourage students to identify unknowns, decompose numbers, and discuss their strategies with the group.

Real-World Application:

Ask students how addition and subtraction apply to real-life situations, such as shopping or playing sports. Explain how decomposing problems into smaller steps helps them solve more complex problems efficiently, both in math and in everyday life.

Equity and Access: 

Provide differentiated word problems with varying difficulty levels to accommodate different learners, and offer manipulatives such as visual aids or digital tools for students who may need additional support. Pair students with peers of varying abilities to promote collaborative learning and ensure that all students are engaged in the problem-solving process.

CS Practice(s):

• Recognizing and Defining Computational Problems: Students break down word problems into manageable steps, identifying key information and determining how to solve them.

• Developing and Using Abstractions: Students use symbols to represent unknowns and abstract mathematical relationships, fostering early computational thinking.

Standard(s):

• CCSS.MATH.CONTENT.1.OA.A.1

• CA CS K-2.AP.13

Objective:

Students will use Scratch Jr. to create interactive animations that model word problems involving addition and subtraction within 20. Through coding, students will visualize and solve problems, using a symbol for unknowns and applying computational thinking skills.

Materials Needed:

• Tablets or computers with Scratch Jr. installed

• Word problem cards for reference

Steps:

• Introduction:

  • Start by reviewing the concept of addition and subtraction using familiar examples. 

  • Then, introduce Scratch Jr. as a tool to create digital stories that show how math problems can be solved. 

  • Explain that they will build animations to demonstrate how characters solve word problems, such as adding apples to a basket or subtracting fish from a pond.

• Group Activity:

  • In pairs, students will select a word problem (e.g., "You had 7 books and bought 3 more. How many books do you have now?"). 

  • They will then use Scratch Jr. to animate the scenario. 

  • For example, they can drag and drop characters to show a cat collecting apples, using code blocks to represent the process of addition or subtraction. 

  • They will program their characters to display the solution at the end, encouraging them to think through each step of the sequence.

• Testing and Refining:

  • Students will run their code to ensure that the animation accurately represents the word problem and solution. 

  • They can test and refine their project by adjusting the sequence of events or adding more detail to their animations. 

  • After testing, they will share their animations with the class.

Equity and Access:

 Offer pre-built Scratch Jr. templates for students who need additional support with coding. Provide step-by-step coding guides for students who are new to Scratch Jr., and encourage peer collaboration by pairing students with varying levels of experience. Ensure access to touch-screen devices or alternative input methods for students with motor skill challenges.

Real-World Application:

Discuss how coding helps us model and solve problems in many areas, including science and math. Students can relate this activity to real-world problem-solving, where breaking down complex tasks into smaller steps and using tools like computers helps to find solutions more efficiently.

CS Practice(s):

• Creating Computational Artifacts: Students use Scratch Jr. to design animations that represent and solve word problems.

• Testing and Refining Computational Artifacts: Students test their animations and refine their code to ensure it accurately depicts the problem and solution.

Standard(s):

• CCSS.MATH.CONTENT.1.OA.A.1

• CA CS K-2.AP.13