Building Number Place Value

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Building NumberPlace Value
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Whats It All About?
You are going to recap or learn How to read and
write large numbers written in digits. How to
compare and order whole numbers. What skills
should you have already? You need to be able to
read, write and compare numbers up to 999.
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Recap on Place Value
Read these numbers
980
Nine hundred and eighty
908
Nine hundred and eight
98
Ninety eight
The position of each digit in the number makes a
difference to its value.
As the place value changes the number changes...
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Recap on Place Value

• Remember the position of a digit changes its
  value!
• Digits are grouped in threes...
• Read these numbers.

Thousand Thousand Thousand
Hundreds Tens Units Hundreds Tens Units
3 5 1
3 2 7 0 9
7 5 6 1 5 0
The decimal number system is based on the number
10
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Recap on Place Value

• Numbers dont just happen - they have
  structure!
• 1 ten 10 units
• 1 hundred 10 tens
• 1 thousand 10 hundreds and so on ...

Thousand Thousand Thousand
Hundreds Tens Units Hundreds Tens Units
3 5 1
3 2 7 0 9
7 5 6 1 5 0
10 of these makes
1 of these
1 of these
1 of these
1 of these
1 of these
10 of these makes
10 of these makes
10 of these makes
10 of these makes
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Recap on Place Value

• If there are more digits, the table needs more
  columns...
• Read these numbers.

Million Million Million Thousand Thousand Thousand
Hundreds Tens Units Hundreds Tens Units Hundreds Tens Units
2 4 1 2 3 0 5
1 4 0 3 0 8 1 0
1 5 2 6 2 1 0 0 0
Digits on the left are worth more than digits on
the right.
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Writing Large Numbers
Writing a number in digits is easy if you picture
the place value table
Write this number in digits. Six hundred and two
thousand five hundred and ninety.
Thousand Thousand Thousand
Hundreds Tens Units Hundreds Tens Units

6 0 2
5 9 0
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Your Turn
1. Four hundred thousand one hundred and sixty
six.
400 166
2. Ninety one thousand six hundred and twenty one.
91 621
3. Seventeen thousand and thirty five.
17 035
4. Two million, three hundred thousand and
seventy seven.
2 300 077
5. Ten million, seventy one thousand four hundred
and two.
10 071 402
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Comparing/Ordering Numbers
Write the numbers in the correct order of
size. Start with the smallest.
49 562 235 280 7 320 1 253 762
7 320
49 562
235 280
1 253 762
The 4-digit number is smallest...
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Comparing/Ordering Numbers
Write the numbers in the correct order of
size. Start with the largest.
349 562 235 280 394 320 253 762
394 320
349 562
253 762
All the numbers have 6 digits, so compare from
the left ...
235 280
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Your Turn
Write the numbers in the correct order of
size. Start with the smallest.

1. 99 562 135 980 8 320 7 253 762
2. 35 565 71 623 19 819 17 368
3. 4 793 162 4 703 762 4 910 724
4. 1 703 762 805 122 851 724

8 320 99 562 135 980 7 253 762
17 368 19 819 35 565 71 623
4 703 762 4 793 162 4 910 724
805 122 851 724 1 703 762
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Multiplying Integers by 10, 100 etc
Recall the place value table...
Thousand Thousand Thousand
Hundreds Tens Units Hundreds Tens Units
5
5 0
5 0 0
5 0 0 0
5 0 0 0 0
5 0 0 0 0 0
? 10
? 10
? 10
? 10
? 10
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Multiplying Integers by 10, 100 etc
Thousand Thousand Thousand
Hundreds Tens Units Hundreds Tens Units
5
5 0
5 0 0
5 0 0 0
5 0 0 0 0
5 0 0 0 0 0

The zeros act as placeholders making sure the 5
is in the correct place value each time...
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Multiplying Integers by 10, 100 etc
To multiply by 10, one place-holding zero is
needed. How many place-holding zeros are needed
to multiply by 100? How many place-holding zeros
are needed to multiply by 1000? Is there a
pattern?
Two
Three
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Dividing Integers by 10, 100 etc
Again recall the place value table...
Thousand Thousand Thousand
Hundreds Tens Units Hundreds Tens Units
2 0 0 0 0 0
2 0 0 0 0
2 0 0 0
2 0 0
2 0
2
? 10
? 10
? 10
? 10
? 10
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Dividing Integers by 10, 100 etc
Thousand Thousand Thousand
Hundreds Tens Units Hundreds Tens Units
2 0 0 0 0 0
2 0 0 0 0
2 0 0 0
2 0 0
2 0
2
The place-holding zeros are removed each time the
number is divided by 10 to move the 2 to the
correct place value...
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Dividing Integers by 10, 100 etc
To divide a number that has place-holding zeros
on the right by 10, one place-holding zero is
removed. How many place-holding zeros must be
removed to divide by 100? How many place-holding
zeros must be removed to divide by 1000? Is
there a pattern?
Two
Three
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Your Turn
Work out.

1. 34 000 ? 10
2. 3 554 ? 100
3. 793 162 ? 10
4. 1 703 700 ? 100

3 400
355 400
7 931 620
17 037
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Dividing Integers by 10, 100 etc
To divide a number that has place-holding zeros
on the right by 10, one place-holding zero is
removed. What if the number does not have any
place-holding zeros to remove?
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End