Learning Intention: Students will be able to understand and apply the concept of mass in grade mathematics.

Introduction: Begin the lesson by asking students if they know what mass is. Allow them to share their ideas and definitions. Then, explain that mass is the amount of matter in an object. It is measured in units such as grams (g) and kilograms (kg).

Body: 1. Mass of Objects: Show students different objects of varying mass and ask them to estimate which object is heavier or lighter. Then, use a balance scale to measure the mass of each object and compare their estimations with the actual mass. This will help students understand the concept of mass and how it is measured.

1. Units of Mass: Explain to students that mass is measured in units such as grams and kilograms. Show them how to convert between these units. For example, 1 kilogram is equal to 1000 grams. Provide examples and practice problems for students to work on.

2. Adding and Subtracting Mass: Teach students how to add and subtract mass using units such as grams and kilograms. Provide examples and practice problems for students to work on. For example, if a bag of apples weighs 2 kilograms and another bag weighs 1.5 kilograms, what is the total mass of the two bags?

Conclusion: Review the key concepts covered in the lesson, including the definition of mass, units of mass, and adding and subtracting mass. Encourage students to practice these skills at home and in their daily lives.