The Daily Gas Budget: teacher key

Burps and Farts, grade 6 edition, written for 6th grade. Your body takes in and makes gas all day, and not all of it comes out the way you might think. Follow the gas through the day, with real numbers.

Read the book. Print this page for the key.

Questions and answers

1. What are the two main sources of gas in the digestive tract?
   • Swallowed air and bacteria breaking down food (answer)
   • Water and salt
   • Sleep and exercise
2. About how much gas do people pass on average in a day?
   • About 6 liters
   • About 600 to 700 milliliters (answer)
   • About 20 milliliters
3. Why does a lot of gas never leave through the bottom?
   • It is absorbed into the blood or burped up first (answer)
   • It turns into food
   • It is too heavy
4. What does absorbed mean on these pages?
   • Soaked in (answer)
   • Thrown out
   • Smelled
5. How much of fart gas is made of hydrogen, methane and carbon dioxide?
   • About one percent
   • About three quarters (answer)
   • None of it
6. Why can two people have different amounts of gas?
   • Air swallowed and foods eaten differ (answer)
   • Only one has a large intestine
   • Gas is only made at night

Words

• absorbed: soaked in
• ferment: break down food
• carbohydrate: sugar or starch
• hydrogen: a light gas
• lactose: milk sugar