150 Pounds of Garlic

Herb Garden, Kline Creek Farm, by Erika Smith.  Image retrieved from Wikimedia Commons

By Clarence Thompson
I have been very busy for the last two months with community organizing.  The last three weeks have been especially interested as I am taking an online class related to creating social movements for change and liberation.  Therefore, I haven't had time to contribute to this blog.

However, our Flying University Project is going quite strong, and our North Portland teaching group is in full swing.  We are also continuing to work on our Book 4.  For the next few weeks, I'll post previews of some of the material we are including in this book.  Here's a word problem for readers to chew on.  Feel free to try it out yourselves or with your children - and feel free to send comments or suggestions for improvement.

Example: Planning a Garden

Let’s say that you live near a community garden, and the people who run the garden have let you use one of their garden plots to grow vegetables. You can grow 150 pounds of garlic in your plot, but you have to use 60 gallons of water and two bags of fertilizer. To pay for the water and fertilizer, you can use pennies or dollar bills. One dollar is worth 100 pennies. Here are three questions:

• If the water costs 30 pennies per gallon and each bag of fertilizer costs $6, how much does it cost you to grow 150 pounds of garlic?
• How many pounds of garlic can you grow for each dollar you spend?
• If garlic costs $2 per pound at the store, is it cheaper for you to grow your own garlic or to buy it at the store?

For question #1, we ask four problem-solving questions:

What do we already know? We know these things:

• Your plot can grow 150 pounds of garlic
• Growing 150 pounds of garlic uses 60 gallons of water
• Water costs 30 pennies per gallon
• Fertilizer costs $6 per bag

What question are we trying to answer? We want to know how much it costs you to grow 150 pounds of garlic.

Can we turn the question into an equation? Yes! There will be three equations and they will look like this:

If we put the numbers we already know into these equations, we get these results:

Can we solve these equations to find the answer to Question #1? Yes! Solving these equations gives these results:

Now that we know how much it will cost to grow 150 pounds of garlic, we can figure out how much garlic we can grow for each dollar spent. The equation looks like this:

See if you can solve this equation by yourself. Once you have the answer, see if you can tell which is cheaper: growing garlic yourself or buying it from the store.