# Tall Tails

Height can be measured in some rather strange units.

## How it works

Young children can measure their height against a ruler, or a stack of monkeys and other animals.

## Things to try or ask around the exhibit

What's your height in monkeys? How do you record your height if you reach part-way on a monkey?

## Background

We can use centrimetres and the monkeys as a measure, but not the stack of animals, because they are not equal units within the scale. The monkeys are roughly equal units in the monkey scale, but the best scale to use would be the centimetre ruler.

When you measure your height, you need to think about how accurately you want to measure. For example, you could measure your height in metres, but measuring in centimetres would be accurate, while measuring in millimetres would be even more accurate.

## Finding the science in your world

If a person accurately measures their height in the morning and then again in the afternoon, they would find that their height differs by a few millimetres (even when they have stopped growing). This is because over the course of the day, a person's spinal vertebrae compress slightly due to gravity, causing a slight shrinkage in height.