Grades 3-5 Math Problem Solving in Action_ Getting Students to Love Word Problems

(Marvins-Underground-K-12) #1

Figure 2.8 Multiplicative Comparison Problems


Problem Types Bigger Part
Unknown

Smaller Part
Unknown

Difference
Unknown
(Number Times
as Many)
Compare Marco has 5
marbles. His
brother has 2
times as many
as he does. How
many more
marbles does his
brother have than
he does? How
many do they
have altogether?

Luke has 10
marbles. He has
2 times as many
as Marco. How
many does Marco
have?

Marco has 5
marbles. Luke
has 10 marbles.
How many times
as many marbles
does Luke have as
Marco?

Bar Diagram
Modeling
Problem 5

5 5
?

5 5

5

5

5 5

What are we
looking for?
Where is X?

In this type of
story, we are
comparing two
amounts. We
know the smaller
amount and we
have to find the
larger amount.

In this type of
story, we are
comparing two
amounts. We
are looking
for the smaller
part which is
unknown.

In this type of
story, we are
comparing
two amounts.
We know both
parts but we are
looking for how
many times as
many the larger
part is than the
smaller part.
Algebraic
Sentence

5 × 2 = 10
10 + 5 = 15

10 ÷ 2 = 5 5 ×? = 10 or
10 ÷ 5 = 2
Strategies to
Solve

Multiply
Addition

Divide Multiply or divide

Answer His brother
had 10 marbles.
Altogether they
had 15 marbles.

Marco had 5
marbles.

Luke had 2 times
as many marbles
as Marco.
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