Whole Number Calculations
TIMES TABLES
Answer any question from the times tables within 2 seconds.
ADDITION
Add 2 or more whole numbers together.
e.g. 638 + 425
Step 1
Set up the calculation.
Step 2
Add the units column.
8 + 5 = 13
Write in the 3, carry the 1 into the next
column.
Step 3
Add the Tens column, remember the 1
that has been carried over.
Step 4
Add the Hundreds column.
6 + 4 = 10
Write the 3 in the Hundreds column,
carry the 1 into the Thousands column.
+
6
4
3
2
8
5
+
6
4
3
21
8
5
3
+
6
4
3
21
6
8
5
3
+
1
6
4
0
3
21
6
8
5
3
-
8
3
2
6
1
5
SUBTRACTION
Subtract whole numbers.
e.g. 821 – 365
Step 1
Set up the calculation.
Subtract the Units column.
1 – 5 you can’t do.
Step 2
Borrow 1 from the Tens column.
8
3
1
2
6
8
3
1
2
6
-
8
3
1
2
6
1
-
7
8
3
1
-
7
8
3
7
8
3
4
1
-
Step 3
Subtract the Units column.
11 – 5 = 6
-
Step 4
Subtract the Tens column.
1 – 6 you can’t do.
Step 5
Borrow 1 from the Hundreds column.
Step 6
Subtract the Tens column.
11 – 6 = 5
Step 7
Subtract the Hundreds column.
7–3=4
-
1
2
6
1
2
6
5
1
2
6
5
1
1
5
1
1
5
6
1
1
5
6
1
1
5
6
1
1
5
6
1
1
5
6
MULTIPLICATION
Multiplication by whole numbers less than 10.
e.g. 365 × 8
Step 1
Set up the calculation.
3
6
5
8
3
6
4
5
8
0
4
5
8
0
4
5
8
0
×
Step 2
Multiply the 1s digit in the top row by
the multiplier.
i.e. 5 × 8 = 40
Put the 0 in the answer and carry the 4
into the next column.
Step 3
Multiply the Tens digit in the top row by
the multiplier.
i.e. 6 × 8 = 48
now add the carried number
i.e. 48 + 4 = 52
Put the 2 in the answer and carry the 5
into the next column.
Step 4
Multiply the Hundreds digit in the top
row by the multiplier.
i.e. 3 × 8 = 24
now add the carried number
i.e. 24 + 5 = 29
Put the 29 in the answer.
×
3
×
6
5
2
3
×
2
6
5
9
2
MULTIPLYING BY 10
When we multiply a whole number by 10 we move ALL digits 1 place to the LEFT.
e.g. 54 × 10
H
T
5
4
5
1s
4
0
This gives 5 Hundreds,
4 Tens and we add a 0
to the 1s column.
The shortcut for multiplying a whole number by 10 is to add a zero to the end of the number.
284 with a zero added.
e.g. 284 × 10 = 2 840
MULTIPLYING 100
When we multiply a whole number by 100 we move ALL digits 2 places to the LEFT.
e.g. 72 × 100
Th
H
7
T
7
0
2
1s
2
0
This gives 7 Thousands and 2
Hundreds, we add a 0 to the
Tens and 1s columns.
The shortcut for multiplying a whole number by 100 is to add 2 zeros to the end
of the number.
93 with 2 zeros added.
e.g. 93 × 100 = 9 300
MULTIPLYING BY 1 000
When we multiply a whole number by 1 000 we move ALL digits 3 places to the LEFT.
e.g. 26 × 1 000
TTh Th
2
6
H
0
T
2
0
1s
6
0
This gives 2 Ten Thousands and 6
Thousands, we add a 0 to the
Hundreds, Tens and 1s columns.
The shortcut for multiplying a whole number by 1000 is to add 3 zeros to the end
of the number.
49 with 3 zeros added.
e.g. 49 × 1 000 = 49 000
DIVISION
Division by whole numbers less than 10.
e.g. 1827 ÷ 7
Step 1
Set up the calculation.
Step 2
Divide the first digit by 7.
1.e. 1 ÷ 7 = 0 r 1
Write the 0 in the answer space and
carry the 1 onto the next digit.
Step 3
Divide the next number, including the
carried digit by 7.
1.e. 18 ÷ 7 = 2 r 4
Write the 2 in the answer space and
carry the 4 onto the next digit.
Step 4
Divide the next number, including the
carried digit by 7.
1.e. 42 ÷ 7 = 6 r 0
Write the 6 in the answer space. Zero
remainder so nothing to be carried on.
Step 5
Divide the next number by 7.
1.e. 7 ÷ 7 = 1 r 0
Write the 1 in the answer space. Zero
remainder so nothing to be carried on.
7
1
8
2
7
7
0
1
1
8
2
7
7
0
1
1
2
8
4
2
7
7
0
1
1
2
8
4
6
2
7
7
0
1
1
2
8
4
6
2
1
7
DIVIDING BY 10
When we divide a whole number by 10 we move ALL digits 1 place to the RIGHT.
e.g. 370 ÷ 10
H
3
T
7
3
1s
0
7
·
·
·
t
This gives 3 Tens, 7 1s
and 0 tenths.
0
We do not need to include the point zero in the answer so 370 ÷ 10 = 37
The shortcut for dividing a whole number by 10 is to remove a zero from the end
of the number.
50 with a zero removed
e.g. 50 ÷ 10 = 5
DIVIDING 100
When we divide a whole number by 100 we move ALL digits 2 places to the RIGHT.
e.g. 3 400 ÷ 100
Th
3
H
4
T
0
3
1s
0
4
·
·
·
t
h
0
This gives 3 Tens, 4 1s, 0
tenths and 0 hundredths.
0
We do not need to include the point zero zero in the answer so 3400 ÷ 100 = 34
The shortcut for dividing a whole number by 100 is to remove 2 zeros from the end
of the number.
6 700 with 2 zeros removed
e.g. 6 700 ÷ 100 = 67
DIVIDING BY 1 000
When we divide a whole number by 1 000 we move ALL digits 3 places to the RIGHT.
e.g. 9 000 ÷ 1 000
Th
9
H
0
T
0
1s
0
9
·
·
·
t
0
h
0
th
0
This gives 9 1s, 0 tenths,
0 hundredths and 0
thousandths
We do not need to include the point zero zero zero in the answer so 9 000 ÷ 1 000 = 9
The shortcut for dividing a whole number by 1 000 is to remove 3 zeros from the end
of the number.
28 000 with 3 zeros removed
e.g. 28 000 ÷ 1 000 = 28
Whole Number Calculations Practice
www.thatquiz.org
Select Arithmetic under the Integers heading.
Tick the boxes for ADDITION and either LONG A or LONG B. Answer the questions.
Repeat for subtraction, multiplication and division.
Repeat this activity regularly, try to improve the time taken for each set of questions.
Try the questions again selecting the INVERTED option.
www.supermathsworld.com Ask your teacher for login details.
Select Number from the options.
Select ADDITION from the menu.
Try the Easy, Medium and Hard levels. Do these questions MENTALLY.
Repeat for SUBTRACTION, TIMES TABLES and DIVISION.
Regular Brain Training on a Nintendo DS or other websites is also good way to improve numeracy skills.