03 Integers Absolute Value

advertisement
Understanding Integers ~ Lesson 3
Absolute Value
Students will understand that absolute value is
the distance of a number from zero on the
number line. The absolute value is always
positive.
Teaching Actions:
Materials
•Whiteboard
•Smartboard or chalkboard
•Pre-made Number Line
•Pre-made integer strips
•Tag board/construction
paper with the number 0
written on it – 1 per student
Comments
1. Give each student a zero card.
Tell them they are going to walk an imaginary
number line.
Have each student put their card on the
ground and stand on it. 0 is home base – all
integers start from 0. Determine as a class
which direction is positive and which direction
is negative.
Ask students to turn so they are facing the
direction of the positive integers. Have them
take 3 steps. Ask how many steps away from
0 they took (3). Have students return to home
base, or 0. Have students turn to face the
negative integers. Have them take 3 steps.
Ask how many steps away from 0 they took
(3). Many students will say 3. Explain why
you can’t take 3 steps.
Continue this until all students understand that
it doesn’t matter what direction you are facing.
It is the distance from zero that matters.
07-15-10
Lesson 3
p. 1
Understanding Integers ~ Lesson 3
Teaching Actions:
Comments
2. Define absolute value and discuss the
symbol for absolute value.
Have students practice by having them tell
what the absolute value of a number is, writing
the absolute value in symbolic form, and
stating which two numbers have the same
absolute value. (i.e. The two numbers that
have the absolute value of 3 are 3 and 3).
Students should explain why two numbers can
have the same absolute value. Introduce the
integer strips as a model.
If some students continue to say a negative
number for an absolute value (many students
get stuck thinking absolute value is the
opposite), have them take out their integer
strips and place integers on the number line
and count how many spaces away from 0 the
integer is.
07-15-10
4
= 4
 4 = 4
Absolute value is the
distance of a number from
zero on the number line.
The absolute value is
always positive.
Deliberately use language that
refers to both distance and
area. For example, “A distance
of five from zero” and/or “five
squares from zero” and/or “a
magnitude or value of 5.”
Students naturally relate area to
value more readily than length
to value.
Lesson 3
p. 2
Download