Math Fact Strategy Seed Ideas
Addition and Subtraction
(based on Teaching Student-Centered Mathematics, 2006)
Zero Strategy
The “zero” strategy is used when zero is on of the addends in the number sentence. This is by
far the easiest strategy for students, but time needs to be spent with young students
developing this strategy. Students should use the commutative property to be able to apply
this strategy to twice as many facts.
Seed Idea: Adding Zero Strategy Cards
 Addition: Choose a card and fold back the flap with zero dots on it so that students
cannot see it. Ask them to tell you how many dots they can see without counting. Then
fold the flap forward and ask students to tell you how many dots there are total. You
could also start with the zero dots and then flip the other half to demonstrate the
commutative property. Repeat this activity several times with different cards.
 Subtraction: Ask the students about the total dots that they see, and then fold back
the larger number part, so that the zero dots is showing. Have the students count back
that number of dots.
Seed Idea: Zero Strategy Flashcards
Addition: Show the flashcard and have them use the zero strategy to solve the fact. This
should only be used after extensive work with the meaning of operation and application of the
strategy. You could also use number tiles and have students match the sum on the digit cards
with the corresponding card.
Seed Idea: Zero Turn around Cards
 Addition: Show the turn around card to students and have them tell you the number
sentence that it represents. (9+0=9) Then, turn around the card so that the dots are on
a different side and have them tell you the new number sentence. (0+9=9). Students
should understand that these two have the same sum and that by turning the fact around,
it makes it easier to add zero to the bigger number.

Subtraction: Have them count the total number of dots on the card, and then count back
the specified number of dots. You can also place a sticky note over the larger number of
dots and write the total number of dots on the sticky note, and have them take zero
away. Then, they can take the sticky note off to check their answer. You could also cove
the larger number so that they can realize that if the sum is the same as the addend
shown, that the missing addend will be zero.
Seed Idea: Zero Strategy “Think Addition” Cards
 Addition: Cover the bottom number and ask the students what the total number of dots
would be. Discuss what strategies were used to find the answer.
 Subtraction: Fold down one of the addends and ask them how many dots are missing.
Have the students share the strategies that they used to determine the missing number
of dots.
Seed Idea: Zero Strategy Subtraction Flashcards
 Subtraction: Cut out the flashcards and then fold them on the dotted line. Show the
flashcard and have them use the zero strategy to solve the fact. This should only be
used after extensive work with the meaning of operation and application of the strategy.
Discuss how the two subtraction facts are related.
Seed Idea: Zero Strategy Missing Addend Cards
 Addition: Cut out the flashcards and then fold them on the dotted line. Show them the
missing addend card and have them figure out what the missing addend would be. Have
them share what strategy they used to find the missing addend.
 Subtraction: Have them determine the missing addend and tell what the related
subtraction fact would be.