Schools will argue there is no need for concern with poor handwriting due to the reliance in modern society of computer technology. Most written communication these days is through a computer medium, typically via a keyboard. That is, we now tend to do more typing than handwriting. However, this does not diminish the importance of maintaining good handwriting skills.
There is also the need to effectively communicate this knowledge to others. This may be a teacher or fellow student. In later life it may be a work colleague, such as a manager.
It is the inherent nature of mathematical based sciences to require very detailed and often small characters to be written down. If a student has poor penmanship then the written work will be difficult to follow, even for the student themselves. These technical subjects need many different symbols to represent a large array of quantities. Some of these characters and symbols are quite similar in appearance. Often a student will write the numeral '5' almost exactly the same as the letter 'S'. Or, the letter 't' written by a student similar to the operator '+'. Other examples include writing the numeral '2' indistinguishable from the letter 'Z'. Careless handwriting may also make it difficult to distinguish between upper and lowercase letters. For example, a lower case 'p' sloppily written above the line could be confused for an uppercase 'P'. This is important as there are occasions when an uppercase character represents a different quantity to the lowercase one.
When it comes to handwriting, students often do not realise the importance of a quality writing instrument. A good writing tool can make a significant difference to penmanship. For example, I often see students writing with cheap ballpoint pens that leak globs of ink on the page. Their hand can smudge the ink making their handwriting appear even worse. This can be avoided by using a better quality pen. Today we are spoilt for choice when it comes to pens and pencils. Good quality ballpoint, gel-ink, felt-tip pens, etc. are widely available at reasonable prices. Even the traditional fountain pen is still favoured by many in search of quality handwriting. There are a variety of pencils to choose from too. The two main types are the click pencil and traditional graphite-clay lead inlaid in a wooden stick. Each pencil type is also sold with a range of lead grades. It is a matter of students experimenting with what suits their personal style and needs. Along with the variety of writing instruments available there are also many nib sizes to choose from. For the mathematical sciences I would recommend a maximum of 0.5 or 0.7 mm nib size. A small nib will assist in drawing intricate characters.
Students should also learn how to hold their pen or pencil in the right way. The correct holding technique may have been taught to a student in their formative school years. However, it is easily forgotten and a poor pen holding position habit develops. It can take a concerted effort to relearn the habit of positioning the writing instrument well.
In spite of the heavy use of digital devices in today's society, it is still very important to learn and maintain legible handwriting skills. Students need to learn penmanship and have it emphasised to them until a good handwriting habit develops. This will pay dividends in their studies throughout the remainder of their schooling years.