Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).

Quarter 1
Quarter 2
Relate counting to addition and subtraction (e.g., by counting on 2 to add 2). (Associated with 1.OA.5, Qtr 1)
Revisit through routines and classroom discussion (as necessary) .

Enduring Understanding

Mathematical operations are used in solving problems in which a new value is produced from one or more values.
Algebraic thinking involves choosing, combining, and applying effective strategies for answering quantitative questions.

Essential Questions

In what ways can operations affect numbers?
How can different strategies be helpful when solving a problem?

Vocabulary (online dictionary, HCPSS Vocabulary Cards)

addition, subtraction, count on, count back

About the Math

Students need to see that when they count 2 more or 2 less, they are actually adding 2 and taking away 2. At first, students may identify this with counting instead of the relationships between numbers. We want students to see that 7 is two more than 5 and that 8 is two less than 10. These relationships need to be developed through representation of the sets. Dot plates, calculators, part-part whole models can all be used to represent these relationships.

Rich Tasks for Multiple Means of Engagement, Expression, and Representation (UDL)

1. Counting On with Counters (Van de Walle, K-3, p 41). Give Each child a collection of 10 or 12 small counters that the children line up left to right on their desks. Tell them to count four counters, then push them under their left hand. Then say, "point to your hand. How many are there?" (Four.) "So let's count like this: f-o-u-r (pointing to their hand), five, six, ... Repeat with other numbers under the hand.

Other Teaching Student-Centered Mathematics K-3 Activities include:
Van de Walle, K-3, Activity 2.7 "Real Counting On" page 41
Van de Walle, K-3, Activity 4.1 "One/Two-More-Than Dice" page 100
Van de Walle, K-3, Activity 4.3 "Lotto for +1/+2" page 100

Rich Problems:
Create a set of dot plates with representations of numbers from 1 to 10. Flash a plate up and ask students to show you a set that is two more and/or two less than the number represented. Depending on the level of the students, they can use counters or digit cards to show the number. Counters on an overhead or document camera can also be used as the vehicle for the representation of the number. Give students a four function calculator and ask them to show the number on the calculator. Use prompts such as show me the number that is 2 more than 6.

Journal Prompt:

I subtracted one number from another and got a difference of two. What might the two numbers be?

Print Resources:

Brain Compatible Activities for Mathematics K-1
Math Intervention: Building Number Power K-2
Number Sense 1-2
Mastering the Basic Math Facts
in Addition and Subtraction
Developing Number Concepts
(1-3, 4, 5, 6, 7, 8)

Web Resources:

hcps 092810 630.jpg
hcps 092810 666.jpg
hcps 092810 723.jpg
Games and Centers
Student Resources
Video Segments
Show One More

Show One Less

One More on the 10 Frame

One More/One Less Scoop

Online Games
The Counting Game

Math Magician

Lesson Plans
Frogs On a Logs

How Many More?

Counting On

Lesson Seeds
Splendid Subtraction Activities
Monster Musical Chairs

One More/One Less Number Map
(Michelle Glenn, CLES)
Animals and Numbers

Connecting Children's Literature:

Mouse Count
By Ellen Stoll Walsh


Contact John SanGiovanni at

Use and Sharing of HCPSS Website and Resources:Creative_Commons.png
Howard County Public Schools Office of Elementary Mathematics Curricular Projects has licensed this product under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.