Transcript Place Value

PLACE VALUE
IT’S LOCATION, LOCATION, LOCATION
WARM-UP
• What is the largest number you
can make from these digits?
8,4,6,3,8,7,6,9,0,2,4,6
• What is the smallest number you
can make using the same digits?
WHERE ARE YOU?
• A digit is the term that refers to a single
number (0-9)
• The value of a digit depends on where
it is placed in the numeral.
• The digit 3 is more valuable in 349 than
it is in 439
• Turn to someone at your table and
explain why
9 IS ALL THEY CAN HANDLE
• Place value bars are organized two ways:
• Each bar can only hold up to the value of 9.
• Once the value exceeds 9, the numeral must make a
bundle of 10 and move to the place value on the left.
18 = 1 bindle of ten and 8 single ones
• If we added 5 more to 18, we would have 13 in the
ones column.
• 13 is 1 bundle of ten and 3 single ones
• Therefore 18 + 5 = 2 tens and 3 ones
ARE YOU UP FOR A CHALLENGE??
Let’s experiment with place value
Find a partner to complete this task
Work with your partner to add 8 + 6
You will add using base 5 – this means that each
place value can only hold the digits 0-4. Once you
get to 5 you need to bundle into a 1 and move that
one to the left one place value.
• In base 5, 8 + 6 = 24
• 2 bundles of 5 and 4 left over
•
•
•
•
WANT TO TRY AGAIN?!?
• Let’s stick with base 5
• Work with a partner to complete these problems:
9 + 14
22 + 6
6+2
11 + 7
WANT TO TRY AGAIN?!?
• And the answers are:
9 + 14 = 43 (4-5’s + 3)
22 + 6 = 103 (1group of 25+ 3)
6 + 2 = 13 (1-5 + 3)
11 + 7 = 33 (3-5’s + 3)
WHAT’S THE VALUE?
• As a digit moves to the left, it increases in value
• Proof:
3 < 30 < 300 < 3,000 < 30,000 < 300,000
3
30
300
3000
30,000
300,000
The digit 3 has moved
to the left.
Each jump to the left
has increased the
value.
By how much has the
value increased with
each jump?
WHAT’S THE VALUE?
• As a digit moves to the right, it decreases in value
• Proof:
300,000 > 30,000 > 3000 > 300 > 30 > 3
The digit 3 has moved
to the right.
Each jump to the right
has decreased the
value.
By how much has the
value decreased with
each jump?
3
0.3
0.03
0.003
0.0003
0.00003
COMPARATIVELY SPEAKING
• It is very important that when you compare whole
numbers, you line up the place value column.
• This way you are sure to be comparing tens to tens
and hundreds to hundreds.
• Once you have the place value bars lined up, you
compare the digits. The digit with the greater value
in the same place value column is worth more
3 tens is > than 2 tens or 1 ten
3 tens is < 4, 5, 6, 7, 8 or 9 tens
PRACTICE WHAT YOU KNOW
• Put these numbers in order from greatest (top) to
least (bottom)
35,987
43,800
21,087
35,978
43,080
21086
CHECK YOUR ANSWERS
• And the answers are:
43,800
43,080
35,987
35,978
21,087
21,086
JUST A FEW MORE THINGS
• Standard Form – the regular way you write a
number using digits and place value
35
• Word Form – writing the value of a number using
words instead of digits
thirty-five
• Expanded Form – separating out the digits and
showing the value of each place value
30 + 5
PRACTICE
• Write the following numerals in word form and
expanded form:
21
196
62
16
3,460
13,000,000
TEXTBOOK TIME
• Take out your math spiral.
• Open to the first page and write the
heading:
• 1.1 page 6 Place Value
• Open to page 6 in your textbook
• Read the page and complete numbers 1&2
under Explain It
• Write your responses in your spiral.
• Stand behind your chair when you are
finished.