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Academic Skills Advice
Four Rules Refresher Sheet 1
You need to be confident with the 4 rules of number - add, subtract, multiply and divide. If
you can’t use a calculator you need to be able to do them all by hand.
Add
Starting from the right add the first column. If your answer is bigger than 10, put the units
under the answer line and carry the tens. Continue this pattern for each column (working
left).
Example:
 35 + 47
+
3
41
8
5
7
2
5+7 is 12, put the 2
in the answer line
and carry the ten.
Subtract
Start from the right and always do top number take away bottom number. Put the answer
for each column under the answer line.
If the bottom number is bigger than the top you need to borrow. Borrow one from the next
column along and put a one in front of the original column. Decrease the column you
borrowed from by 1. Now you can take away as normal.
Examples:

95-54
9
5
4

5 take away 4 is 1 then 9
take away 5 is 4.
185-36
1
7
1
8
3
4
2
9
10
1
4
4
-

5
4
1
1
5
6
9
You can’t do 5-6 so borrow from the
8 (leaving 7) and give it to the 5
making 15 (because you borrowed
from the 10’s column.
4
6
7
You can’t do 4-6 but can’t borrow from
0, so borrow from the 2 (leaving 1) and
give it to the 0 making it 10. Now you
can borrow from 10 (leaving 9) and give
it to the 4 making 14.
204-46
1
-
1
1
H Jackson 2008 / Academic Skills
Except where otherwise noted, this work is licensed under
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Multiply
Start with the bottom right number and multiply it by everything on the top row. Put your
answers beneath the answer line. Remember to add a zero underneath the number you
have just finished multiplying by then multiply the next bottom number by everything on the
top row. Add your answer lines together to get a final answer.
Examples:

54 x 3
1
x
1

5
6
4
3
2
3x4 is 12, 2 on the answer line and carry
the 1. 3x5 is 15 and add on the 1 you
carried (16). The answer is 162.
64 x 23
1
x
1
1 12
1 4
6
2
9
8
7
Ignore the 2 and multiply the top row by 3 (as above).
The answer is 192. Put a zero under the 2 in your
answer (to show you have finished with the units
column) then multiply everything on the top row by the 2.
Finally add your 2 answer rows together.
4
3
2
0
2
If you prefer the grid/box method for multiplying see Four Rules Refresher Sheet 2 as a
reminder.
Divide
When dividing you start from the left and divide into one number at a time, carrying any
remainders to the next number.
Example:

1482÷6
(note: this could be written as
6
1
2
4
4
28
7
42
1482
6
)
Start from the left and ask yourself ‘how many 6’s in 1?’
It doesn’t go so ask ‘how many 6’s in 14?’ put the answer
2 on the answer line. Carry the remainder 2 to the 8 then
ask ‘how many 6’s in 28?’ 4 remainder 4. Finally how
many 6’s in 42? Answer 7. The answer is 247.
See Decimals Refresher Sheet 3 for how to add, subtract, multiply and divide decimal
numbers.
H Jackson 2008 / Academic Skills
2
Practice Questions:
+
2
1
7
5
+
4
6
5
3
-
3
1
8
5
+
5
7
4
4
+
5
8
9
5
-
6
2
5
3
+
7
8
5
4
+
3
2
4
7
-
7
5
2
6
+
3
2
2
4
8
7
+
4
3
5
6
7
7
-
3
2
0
4
0
7
1
5
7
4
8
5
4
8
5
7
5
2
0
7
0
3
+
+
-
+
-
-
8
4
5
5
-
2
7
5
x
x
7
2
3
4
-
6
3
4
x
5
5
4
1
-
4
6
6
x
3
1
0
3
6
0
-
4
3
5
7
x
5
3
2
5
0
0
2
3
4
8
X
x
4
6
5
3
3
4
5
6
6
1
9
6
x
5
8
9
5
5
2
1
5
8
2
1
2
H Jackson 2008 / Academic Skills
x
3
2
4
7
4
6
4
x
8
5
2
9
2
1
5
6
7
7
7
8
7
5
4
8
5
1
5
2
3
4
x
4
5
7
÷
5
1
8
3