Addition and Subtraction Concepts 67What is the Adding Doubles and Near Doubles
Concept?
There is something uniquely fascinating about doubles. Often
students are keenly interested in doubles, which propels them to
master these facts earlier than other facts. The smaller doubles
(1+1, 2+2, 3+3, 4+4, 5+5) are often learned quickly. Larger doubles
(6+6, 7+7, 8+8, 9+9) can take more time. To help students learn
doubles, provide many experiences with doubling situations.
Students also need to conceptually understand addition and
the idea of “twice as many.” When students own their doubles,
meaning they do not need to count all or count on, they are ready
to learn how to use this knowledge to solve near double addition
problems. When teaching the near doubles concept, encourage
students to identify the two doubles facts that the near double
falls between and allow them to use plus one or minus one to
solve the equation. For example, 7 + 8 = 15 falls between
7 + 7 = 14 and 8 + 8 = 16. Allow the students to decide which
double they want to use to solve the near double problem.
In this way, students learn more about number relationships.
They know they need to add one or subtract one because they
understand the math involved.CCSS
Operations and Algebraic Thinking
Number and Operations in Base TenFormative Assessment
Analyze the level of ownership by the accuracy and speed
with which the student solves the doubles problems. If the
student owns her doubles, provide near doubles problems
and ask her to explain how she solved them. Identify which
doubles and near doubles the student does and does not own.Adding Doubles and Near Doubles
CONCEPT: