Lesson 11Representing Small Numbers on the Number Line
Learning Goal
Let’s visualize small numbers on the number line using powers of 10.
Learning Targets
I can plot a multiple of a power of 10 on such a number line.
I can subdivide and label a number line between 0 and a power of 10 with a negative exponent into 10 equal intervals.
I can write a small number as a multiple of a power of 10.
Warm Up: Small Numbers on a Number Line
Problem 1
Kiran drew this number line.
Andre said, “That doesn’t look right to me.”
Explain why Kiran is correct or explain how he can fix the number line.
Activity 1: Comparing Small Numbers on a Number Line
Problem 1
Label the tick marks on the number line.
Plot the following numbers on the number line:
A.
B.
C.
D.
Which is larger,
or ? Estimate how many times larger. Which is larger,
or ? Estimate how many times larger.
Activity 2: Atomic Scale
Problem 1
The radius of an electron is about 0.0000000000003 cm. Write this number as a multiple of a power of 10.
Decide what power of 10 to put on the right side of this number line and label it.
Label each tick mark as a multiple of a power of 10.
Plot the radius of the electron in centimeters on the number line.
Problem 2
The mass of a proton is about 0.0000000000000000000000017 grams.
Write this number as a multiple of a power of 10.
Decide what power of 10 to put on the right side of this number line and label it.
Label each tick mark as a multiple of a power of 10.
Plot the mass of the proton in grams on the number line.
Problem 3
Point
Write the wavelength of the X-ray as a multiple of a power of 10.
Write the wavelength of the X-ray as a decimal.
Lesson Summary
The width of a bacterium cell is about
Note that the right side is labeled
The power of ten on the right side of the number line is always greater than the power on the left. This is true for positive or negative powers of ten.