The reading and writing ruler is designed to help children with both the writing and reading skills that are asked to develop almost simultaneously.
Writing:
When children start learn to write, they don’t leave spaces between words. The pattern has a finger designed in the correct thickness, corresponding to the thickness of the child’s finger. Children place this finger at the end of each word they write, so they visually estimate the space that should be left between words and gradually acquire this skill by eliminating the need for a ruler.

Reading:
When children are asked to read in paragraphs if they do not place their finger where they are reading they usually lose track of where they were reading, and have difficulty locating it. The ruler when turned with the finger down is a helpful tool so that they don’t lose the point where they were reading.