Math Intervention 3–5 Grade

Addition and Subtraction Concepts 39

What is Number Line Profi ciency?

Number line profi ciency involves understanding the order

and spacing of numbers assigned to points on a line. Even

though every point on a number line has a unique real number

(including fractions of fractions), students need to begin

with number lines that have the counting by ones points

labeled before moving to more complex labels. Number line

profi ciency includes knowing that on a horizontal number line,

movement to the right represents addition and movement to

the left represents subtraction. In addition to horizontal number

lines, students should also have experiences with vertical

number lines. Experiences with number lines that are separated

into line segments, such as hundred charts and calendars, and

circular number lines (technically not lines), such as analog

clocks are also benefi cial. Using number lines helps students

build understanding of computation and number relationships.

CCSS

Operations and Algebraic Thinking

Number and Operations in Base Ten

Formative Assessment

To fi nd out if a student has number line profi ciency, show parts

of various number lines and see if students can fi ll in the missing

numbers. Notice if the student quickly identifi es the correct

missing numbers. Look for patterns in strategies and in errors.

Number Line Profi ciency

CONCEPT: