Addition and Subtraction Concepts 85
Rigorous Problem Solving with the Concept of
Partial Sums 1
After a long day of collecting seashells on the beach, Kayla
separated the perfect seashells from the chipped seashells.
There were 39 chipped seashells and 25 perfect seashells.
Part A
Which equation uses a place value strategy to represent the
total number of seashells Kayla collected?
o 39 + 25 = 50 + 14
o 39 + 25 = 12 + 7
o 39 + 25 = 50 + 4
o 39 + 25 = 38 + 24
o 39 + 25 = 50 + 16
Part B
What if Kayla found 3 more perfect seashells and 6 more
chipped seashells?
Write an equation that uses a place value strategy to represent
the new total of seashells Kayla collected.
© 2016, Math Intervention: Grades 3–5, Jennifer Taylor-Cox, Routledge