Written by Samantha Ellingsworth.
When most people think of math, they think of numbers, equations, and the letter x. However, writing and math can go handinhand in the learning process. Writing can help students think about ideas in new ways and develop critical thinking skills while involving students directly in the learning process. Teachers can see a studentsâ€™ thought process, understanding, and where they need more help. In the case of writing and math, writing about math can help develop a personal connection, allowing students to clarify and take charge of their learning and make connections to the real world through reallife applications.
Writing about math can engage students in:
 Problemsolving
 Reasoning and proof
 Communication
 Connections and reallife applications
 Representations
Writing to explain how a problem was solved is a common and valuable form of mathematical writing. That said, there are many other ways of writing about math. Students can keep learning journals/blogs, free write for a period of time, create word problems, define vocabulary, write oneminute essays, or write creatively (math poetry, math mad libs, math jokes).
Here are 7 fun writing topics or prompts:

How long do you think it would take you to count to a million by ones? What makes you think that?

How are the numbers 10 and 100 alike? How are they different?

What is your favorite shape? Why do you like it?

How many measurements can you think of to describe yourself? (Height, weight, shoe size, etc.)

Explain how you could multiply 5 x 78 in your head.

Make up a word problem involving cooking and fractions.

If you could be any number from 1 to 100, which would you be, and why? Which numbers would you choose for friends and family members?
One of the ways to get students interested in writing about math is to make it fun. Teachers can create an environment in which writing about math is a positive learning experience by engaging students with enjoyable activities. Parents can also help do this at home.
Source: https://www.educationworld.com/a_curr/mathchat/mathchat014.shtml