The numerical expression to model the situation when Kristen read her book is 2 + 1.
<h3>What is a numerical expression?</h3>
A numerical expression simply refers to the mathematical statements which have at least two terms which are related by an operator and contain either numbers, variables, or both. Addition, subtraction, multiplication, and division are all possible mathematical operations.
In this case, Kristen read her book for 2 hours after school, then she read for another hour before she went to sleep. The expression will be:
= 2 + 1
= 3
She read for 3 hours.
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