Today was our last day of studying the Skeletal System. We started by naming the different bones we’ve learned on “Joe” (our skeleton model, from “Ein-O’s Human Biology: Skeleton Box Kit”). I was surprised at how many bones the kids remembered. (And surprised at how many I had forgotten. Shh. Don’t tell them.)

We then read The Bones You Own, by Becky Baines. This book is published by National Geographic Kids and is great, but simple overview of the bones in our bodies and their purposes. At the end, there’s a picture of a skeleton that we named more bones on. By this time, even my 5 year old is doing quite well at remembering lots of bones, including some of the scientific names!

Then it was time to discover what had happened to the chicken bones that have been sitting in vinegar for the last week or so. We pulled out the baggie of regular chicken bones (that have been stored in the refrigerator for the past week), and opened the jar of vinegar and put those bones on a paper plate to investigate further. Each of the kids felt the original bones to remind themselves how hard and tough bones normally are. Then they took turns bending the vinegar bones. With lots of exclamations of, “Eww!” and “Gross!!” they discovered that the bones that had been in vinegar all this time had become rubbery and bendable. This opened the door perfectly to a discussion about bones being made of calcium (which the vinegar had effectively dissolved), which we get from milk and other foods.

Lastly, we cut open the bone lengthwise to study the layers inside. More exclamations of disgust erupted, but all three were fascinated to see the marrow and spongy bone so clearly. After discussing each layer and their purpose, we labeled a cross-section diagram from The Human Body, Grades 5-8: 100+ Reproducible Activities. You could also use this diagram from KB Teachers to do the same thing. We also enjoyed the picture in DK Eyewitness Books’ Human Body. This whole book has really interesting photographs of the inside of the body that are either really life-like models, or are actually from cadavers. (If you have young or sensitive ones looking on, you might want to preview this book ahead of time as some kiddos might find the life-likeness to be a bit unnerving.)

For our last activity of the day, I gave each kid their own copy of a crossword puzzle from The Human Body, Grades 5-8: 100+ Reproducible Activities that shows a diagram of a skeleton with a word bank of the matching bones’ scientific names. My 9 and 7 year olds were able to complete this with hardly any help from me, but since all the words in the word bank were the scientific terms, my 5 year old needed help. So, I wrote down the common names of each bone next to the scientific term (ie. next to ‘cranium’ I wrote ‘skull’). From that point on, she flew! I loved watching her little mind work as she crossed off words and filled them in. When she got to the tibia, the shin bone, she said to me, “That’s the shin bone because that’s where Ethan wore his shin guards during soccer.” Such a smarty-pants! Overall, I felt like the crossword puzzle became a great tool for evaluating, or testing, each kid’s retention of the knowledge we’ve acquired over the past week. And they had fun doing it!

Next, we’ll be on to the muscular system. I’m off to do my homework now so that I’ll be ready to hit the ground running tomorrow!