Transcript Building Number Place Value - OCR

Building Number
Place Value
What’s 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.
Recap on Place Value
Read these numbers:
980
908
98
Nine hundred and eighty
Nine hundred and eight
Ninety eight
The position of each digit in the number makes a
difference to its value.
As the place value
changes the number
changes...
Recap on Place Value
Remember – the position of a digit changes its
value!
Digits are grouped in threes...
Thousand
Hundreds
7
Tens
Units
Hundreds
Tens
Units
3
5
1
3
2
7
0
9
5
6
1
5
0
Read these numbers.
The decimal number
system is based on the
number 10…
Recap on Place Value
Numbers don’t just “happen” - they have structure!
Thousand
Hundreds
Tens
Units
Hundreds
Tens
Units
1 of
these
7
10 of
1 of
these
3
these
makes
5
10 of
1 of
these
2
these
makes
6
103of
1 of
these
7
these
makes
1
105of
1 of
these
0
these
makes
5
101 of
9
these
makes
0
1 ten
=
1 hundred =
1 thousand =
10 units
10 tens
10 hundreds and so on ...
Recap on Place Value
If there are more digits, the table needs more
columns...
Million
Hundreds
1
Tens
Thousand
Units
Hundreds
Tens
Units
Hundreds
Tens
Units
2
4
1
2
3
0
5
1
4
0
3
0
8
1
0
5
2
6
2
1
0
0
0
Read these numbers.
Digits on the left are worth
more than digits on the
right.
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
Hundreds
6
Tens
0
Units
Hundreds
Tens
Units
2
5
9
0
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
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...
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
235 280
All the numbers have 6
digits, so compare from the
left ...
Your Turn
Write the numbers in the correct order of size.
Start with the smallest.
1.
2.
3.
4.
99 562
135 980
8 320
8 320
99 562
135 980
35 565
71 623
19 819
17 368
19 819
35 565
4 793 162
4 703 762
4 703 762
4 793 162
1 703 762
805 122
805 122
851 724
7 253 762
7 253 762
17 368
71 623
4 910 724
4 910 724
851 724
1 703 762
Multiplying Integers by 10, 100 etc
Recall the place value table...
Thousand
Hundreds
5
Tens
5
0
Units
5
0
0
Hundreds
5
0
0
0
Tens
Units
5
0
0
0
0
5
0
0
0
0
0
 10
 10
 10
 10
 10
Multiplying Integers by 10, 100 etc
Thousand
Hundreds
5
Tens
5
0
Units
5
0
0
Hundreds
5
0
0
0
Tens
Units
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...
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? Two
How many place-holding zeros are needed to
multiply by 1000? Three
Is there a pattern?
Dividing Integers by 10, 100 etc
Again recall the place value table...
Thousand
Hundreds
Tens
Units
Hundreds
Tens
Units
2
0
2
0
0
2
0
0
0
2
0
0
0
0
2
0
0
0
0
0
2
 10
 10
 10
 10
 10
Dividing Integers by 10, 100 etc
Thousand
Hundreds
Tens
Units
Hundreds
Tens
Units
2
0
2
0
0
2
0
0
0
2
0
0
0
0
2
0
0
0
0
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...
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? Two
How many place-holding zeros must be removed to
divide by 1000? Three
Is there a pattern?
Your Turn
Work out.
1.
34 000  10
= 3 400
2.
3 554  100
= 355 400
3.
793 162  10
= 7 931 620
4.
1 703 700  100 = 17 037
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?
End