> with two small kids I'm very interested to know how. My few perhaps-non-obvious bits: If you find yourself saying "really, really (physically) small", or "N

> with two small kids I'm very interested to know how. My few perhaps-non-obvious bits: If you find yourself saying "really, really (physically) small", or "N times smaller than a human hair", the approach at the top of this[1] might work better. Estimation is now taught down to K... but oh my is it done badly. PBSKids: "estimate how many jellybeans are in the jar: look at the jar; then write down a number!" (really). But it's been a few years since I looked, so maybe there's something competent now. My suggestion is to emphasize bounding, as it supports better conversations. "How many people are reading HN today? Is it more like 1, 10, 100, 1000, 10k, 100k? Who can suggest a bound? Oh, I'm reading HN! So a hard lower bound of 1! Does everyone buy that? ...". Toddler-initiated predictable conversations by pointing out selected elements of the environment. Eg, "a map!" and "rust!". "What does it show? Where are we? Where are we going?". "What's the thing rusting? How's the oxygen getting in? What's the rust doing? What did we have for breakfast, that we're oxidizing now?". The map one works best with urban mass transit and museums and such. Rust is everywhere. [1] How to remember the sizes of small things, top of http://www.clarifyscience.info/part/Atoms http://www.clarifyscience.info/part/Atoms