History and ratios

Epsilons

Time for some history! We put sheets of paper on the wall and drew a long line across all of the sheets. The line was supposed to represent time. And time started with the Big Bang. The girls cut out an image of Big Bang and Jana pasted it to the start of the line.

I asked them who had made this photo and then we talked about the fact that no human had been alive at that time. As a matter of fact, the Earth hadn’t existed yet. While the Big Bang appears to have been 13.5 billion years ago, the formation of the Earth happened 4.5 billion years ago. Meta pasted a photo of the Earth to the timeline. We discussed a little bit how this photo had been taken.

We then talked about the first organisms that emerged 3.8 billion years ago. Vesna pasted the image of some random fish I found on the Internet to the timetable.

I tried to preserve the correct ratio of Big Bang to Earth and Earth to organisms (9 billion years compared to 0.7 billion years). Finally, we pasted Neil Armstrong walking on the Moon close to the end of the timeline. Meta had heard of Armstrong before, but she said Louis Armstrong. I didn’t want to correct her.

At the end, we did a little experiment with water. I poured water into a container and marked the level. Then I poured all the water into two smaller containers and asked to which level it would go if I pour it back into the first container. Jana quickly came up with the correct answer. Yeah, too easy.

Deltas

We sat cross-legged in a circle and I asked if they knew where Turkey is. Marko knew immediately and he showed it on the globe, as well as Syria and Greece. We looked at some other countries on the globe together and I asked whether they knew how old the Earth was. I told them it was 4.5 billion years old. I don’t think they have a very good sense of how much one billion is yet, but they were surprised anyway.

I said we would talk about ratios today and I started with a question: how many Rebekas should we pile on top of each other to get one me? Some said two, some three, some even four. Then I lifted her and showed two Rebekas were significantly higher than me. We agreed that the ratio was somehow 1:1.5.

We then discussed how many things fitted into some other bigger things. Like how many batteries you need to get the height of a book. Or width.

We then measured how many batteries fitted into the length of a rope. They were exchanging roles: one was moving the battery, one was moving the pencil marking the length already measured. The ratio was about 1:50.

Then we discussed the ratio between the years on the timeline. I think they all grasped what I was trying to show. We then pasted some animals to the timeline which were supposed to represent the first animal that came from the sea to the land. Admittedly, I was a little lazy when choosing these pictures.

That was pretty much it, the kids weren’t listening to me anymore and I planned to call it a day.

But Gregor reminded me that the younger group had done some experiments with water. Ah, yeah. So we repeated the simple experiment. It was way too easy, of course. Anway, the kids ended up completely wet and looked totally satisfied with the silly experiment.