Traveling in Time
How long ago was that?
Number lines help you compare numbers and visualize how far
apart they are.
In this lesson you will use a number line to travel back and forth in time.
Thinking about 1’s, 10’s, 100’s and 1,00% makes cou
Mental Math in the
Do you have enough
money to cover the cost
of your purchases?
When you are in the grocery store checkout line, you might
need to make sure that you have enough money with you to purchase all
Close Enuh with
When do you do math .
in your head?
People who are good with numbers do a lot of mental math. A
person who is good at mental math depends on rounding. Rounding is
often used to get an approximate answer, on
How many are there?
How do you know?
Counting is important in our everyday lives. Knowing how to total
the items in a group efﬁciently is valuable because it saves time.
In this lesson, you will look at familiar objects arran
LESSON I I
String It Along
How will this woman
In the last lesson, you looked at the operation of division as a way
to split up an amount into equal parts. You interpreted 52 + 4 as 52
objects split into four piles and $9,600 + 10 as
Extending the Line
What do you wear when
the temperature drops
You have worked with a number line to locate, compare, and ﬁnd
differences between numbers. The numbers were all positive numbers,
greater than zero. In this lesso
What’s the Story?
What math do you see
in this picture?
Solving a problem starts with understanding it: What is the story?
What is happening? Get a picture in your mind. Once you have ﬁgured
that out and have drawn the picture or written a
LESSON I 0
Deal Me In
How much will it
cost per month?
Using mental math strategies can help you make smart and quick
decisions. Savvy consumers often multiply and divide mentally to
predict costs for a year or to break down costs to a per month amoun
Patterns and Order
Which is faster—
mental math or
People who are good at math notice and make good use of
patterns. Keep that in mind as you look for as many patterns as you can
in this lesson’s activities, and use those patterns t
Take Your Winnings
What is the largest
amount you have
Some numbers are easier to work with than others. When you are
doing mental math, some of the most friendly numbers are 10, 100,
In this lesson, you will think ab
Will you spend more than one night in any state? Which one(s)?
Which town is closest to the halfway mark?
How many nights will you spend traveling across the country?
Did you use rounding and mental calculations to arrive at your answers? H