Transcript Whole Numbers

CHAPTER 1
Whole Numbers
Place Value In Whole Numbers
The position a digit has in a number is called its PLACE
VALUE. For WHOLE NUMBERS the PLACE VALUES
are as follows:
Millions
1 000 000
Hundred
Ten
Thousands Hundreds
Thousands Thousands
100 000
10 000
1000
100
Tens
Units
10
1
Non-Calculator Methods for Addition and Subtraction
When adding or subtracting numbers without a calculator
make sure that the columns for each place value are
carefully lined up in the number you are working with.
eg 1
+
187
54
3210
3451
eg 2
1754
- 470
1284
Multiplying a Whole Number by 10, 100, 1000 ….
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When you multiply a whole number by 10 you add 1 zero.
When you multiply a whole number by 100 you add 2 zeroes.
When you multiply a whole number by 1000 you add 3
zeroes.
and so on …...
Multiplying a Whole Number by Multiples of 10 (20, 30, 40..)
Multiply by the number of tens and then multiply by 10.
eg 1
eg 2
537 x 20
412 x 30
537 x 2 = 1074
412 x 3 = 1236
1074 x 10 = 10740
1236 x 10 = 12360
Dividing a Whole Number by 10, 100, 1000 ….
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When you divide a whole number by 10 all digits get moved
1 place to the right.
When you divide a whole number by 100 all digits get moved
2 places to the right.
When you divide a whole number by 1000 all digits get
moved 3 places to the right.
and so on …...
Dividing a Whole Number by Multiples of 10 (20, 30, 40..)
Divide by ten and then divide by the number of tens.
Eg 1
Eg 2
7350 ÷ 50
840 ÷ 20
7350 ÷ 10 = 735
840 ÷ 10 = 84
735 ÷ 5 = 147
84 ÷ 2 = 42
Long Multiplication
Example 1
Work out, without a calculator
417 x 238
Answer 1
417
x
238
3336
12510
+83400
99246
Because we are really multiplying by 30
Because we are really multiplying by 200
Long Division
Example 2
Work out, without a calculator
16422 ÷ 34
Answer 2
00483
3416422
34 x 1 = 34
34 x 2 = 68
34 x 3 = 102
34 x 4 = 136
34 x 5 = 170
34 x 6 = 204
34 x 7 = 238
34 x 8 = 272
34 x 9 = 306
Order of Operations in a Calculation
A useful way to remember the order to do mathematical
operations in, is:
B racket
O ver (powers)
D ivide
A dd
S ubtract