Here's why:
* Syllabication: It has two syllables, making it easier to break down for younger learners.
* Sound-spelling correspondences: Most of the letters in "Columbus" are pronounced as expected, with a few common exceptions like the silent "b".
* Common knowledge: The name "Columbus" is likely familiar to students at this age due to its historical significance.
However, it's important to remember that spelling lists can vary by school and curriculum. Some schools might introduce it earlier or later depending on their specific approach.