Science (EVS K-5) · Class 3 · Food We Eat · Term 1

What Happens to Food Inside Our Body

Tracing the path of food through the digestive system and understanding the roles of different organs and enzymes.

• CBSE Learning Outcomes
• NCERT: Class 7, Chapter 2: Nutrition in Animals

About This Topic

In this topic, students trace the journey of food from the mouth through the digestive system. They learn how chewing breaks down food like roti into smaller pieces with the help of saliva. The food then moves to the stomach where acids and enzymes turn it into a semi-liquid form. From there, it travels to the small intestine for nutrient absorption and finally to the large intestine before exiting as waste.

Different organs play key roles: teeth and tongue in the mouth, stomach muscles for churning, and intestines for extracting goodness. Enzymes speed up the breakdown process, making nutrients available for energy and growth. Simple diagrams and models help Class 3 children grasp this path.

Active learning benefits this topic because hands-on activities like role-playing the digestive journey make abstract processes concrete, helping children remember and apply concepts better.

Key Questions

1. What happens to a roti when you chew it? How does it change?
2. Why do our bodies need to break down food before we can use it?
3. Where does the food you eat go after it leaves your mouth?

Learning Objectives

• Identify the main organs of the human digestive system, including the mouth, stomach, small intestine, and large intestine.
• Explain the role of saliva and stomach acids in the initial breakdown of food.
• Describe how nutrients are absorbed in the small intestine.
• Trace the path of food through the digestive system from ingestion to elimination.

Before You Start

Parts of a Plant

Why: Students should have a basic understanding of different body parts and their functions before learning about internal organs.

Sources of Food

Why: Familiarity with different types of food will help students connect the topic to their own eating habits.

Key Vocabulary

Digestion	The process by which our body breaks down food into smaller molecules that can be absorbed into the bloodstream.
Saliva	A fluid produced in the mouth that moistens food and contains enzymes to start breaking down carbohydrates.
Stomach	A muscular organ that churns food and mixes it with digestive juices containing acid and enzymes.
Small Intestine	A long, coiled tube where most of the digestion and absorption of nutrients takes place.
Nutrients	Substances in food that our body needs to grow, stay healthy, and get energy.

Watch Out for These Misconceptions

Common Misconception

Food goes straight to the blood after eating.

What to Teach Instead

Food must be broken down by digestion in mouth, stomach, and intestines before nutrients enter the blood.

Common Misconception

Digestion happens only in the mouth by chewing.

What to Teach Instead

Digestion continues in stomach with acids and in intestines with enzymes for full breakdown.

Common Misconception

Body uses whole food without changes.

What to Teach Instead

Body breaks food into simple nutrients like glucose for energy and growth.

Active Learning Ideas

Digestive Journey Role-Play

Children form a human chain representing mouth, stomach, and intestines. Pass a ball of roti dough through each 'organ' while describing actions like chewing and mixing with juices. Discuss changes at each step.

25 min·Small Groups

Enzyme Action Demo

Mix biscuit crumbs with water and lemon juice to show breakdown. Compare with dry crumbs to highlight enzyme role. Children observe and note differences.

15 min·Pairs

Food Path Drawing

Draw and label the digestive system on chart paper. Use arrows to show food movement and colour organs. Share drawings with class.

20 min·Individual

What Happens to Roti?

Chew roti, spit into bag, add water and shake to mimic stomach. Observe mushy texture and discuss nutrient release.

20 min·Whole Class

Real-World Connections

• Dietitians and nutritionists help people understand how their food choices affect their digestive health and overall well-being, advising on balanced meals for conditions like indigestion.
• Doctors specializing in gastroenterology diagnose and treat problems related to the digestive system, such as ulcers or difficulty absorbing food, using tools like endoscopes.

Assessment Ideas

Quick Check

Show students a simple diagram of the digestive system with labels missing. Ask them to label the mouth, stomach, small intestine, and large intestine. Then, ask them to draw an arrow showing the direction food travels.

Discussion Prompt

Pose the question: 'Imagine you eat a piece of fruit. What are the first two things that happen to it inside your body and where do these actions happen?' Listen for student responses that mention chewing, saliva, and the mouth.

Exit Ticket

Give each student a small slip of paper. Ask them to write down one organ of the digestive system and one job that organ does. Collect these as students leave the classroom.

Frequently Asked Questions

What happens to a roti when you chew it?

When you chew roti, your teeth break it into small pieces. Saliva mixes with it and starts turning starches into sugars. This makes it easier to swallow and begins digestion, preparing the food for the stomach.

Why do our bodies need to break down food?

Our body cannot use large food pieces directly. Breaking it down into small nutrients allows absorption in the intestines. These nutrients provide energy, help build cells, and keep us healthy.

How does active learning help teach digestion?

Active learning engages children through role-plays and demos, making the invisible digestive process visible. They act as organs or mix pretend food, which builds understanding and retention. It turns passive listening into memorable experiences.

Where does food go after the mouth?

After the mouth, food enters the food pipe to the stomach. There, it mixes with juices and churns into chyme. Then it moves to small intestine for nutrient extraction.