standard_description: Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.
problem_activity: Problem 4
Pre-unit
Find the number that makes each equation true.
\(8 \times 5 = \underline{\hspace{1cm}}\)
\(5 \times \underline{\hspace{1cm}} = 35\)
\( \underline{\hspace{1cm}} \times 2 = 18\)


aligns: no