Sandbags & More Sandbags

Lots of Manual Labor

Sandbags, sandbags, and more sandbags were all I saw for six hours today.  Our sandbagging efforts started at a house on the lake that needed a wall built to use as a break from the waves.  Once we were totally out of bags we were off to fill more bags with sand.  We filled each sandbag with 4 scoops of sand and each pallet had 20 sandbags on top.  Math is used in our everyday life activities without us even realizing it.  Students will always say, “How and when will I ever use this anyway?”  Well doing the math today, let’s just say we loaded 25 pallets.  How would we come to the total number of sandbags completed?  How would we figure out how many scoops of sand was used? 



Sandbag Machine AKA "Sand Spider" ~ Sandbagging went much faster once this machine arrived.

 

Although this problem may be simple, there are a number of ways we could teach our students to solve this problem.  First we know this:  there are 4 scoops of sand per bag, 20 bags per pallet, and 25 pallets.  Second we know that we need to decide what process we are going to use to solve.  Third write out the equation and find the answer.

Step 1 – 4 scoops/bag, 20 bags/pallet, 25 pallets

Step 2 – We could use the multiplication tree model, a set model, and/or array model.  For today I think I will choose the array model to demonstrate this problem.

20 Sandbags/Column                                                                                                     25 Pallets/Row

Step 3 –

20 sandbags per pallet x 25 pallets = ?

20 x 25 = 500 Sandbags

Now we need to take 500 sandbags and figure out how many scoops of sand we did.  To do this we can use the same idea, but remember the process and go from there.

4 scoops per bag x 500 bags = ?

4 x 500 = 2,000 scoops of sand

In the beginning, it did not seem like we did a lot of work.  When you stop and do the math you realize that 2,000 scoops of sand is a big workout and when you get a lot of people together doing this, one or two more people make a world of difference.  So when a student asks, “How will I use this in the real world,” you can help them think of ways that math is used in their everyday activities.

"The Great Sandbag Wall"

Good Luck & Enjoy Teaching

Shelly