Division Basics • Topic 2 of 3

Division as Inverse of Multiplication

Multiplication and division are opposites. One undoes the other. If you multiply $3$ by $4$ to get $12$, then dividing $12$ by $4$ takes you back to $3$. Because of this, every multiplication fact gives you matching division facts.

Fact families. Three numbers that multiply and divide together make a fact family. For $3$, $4$ and $12$:

MultiplicationDivision
$3\times4=12$$12\div3=4$
$4\times3=12$$12\div4=3$

Use your times tables to divide. To work out $42\div7$, just ask: "$7$ times what is $42$?" Since $7\times6=42$, the answer is $42\div7=6$. So learning the tables well makes division quick.

Check your division by multiplying back. To check $36\div6=6$, multiply: $6\times6=36$ — correct! This is the easiest way to be sure a division answer is right.

Why it helps: you do not need to learn division facts separately — they come free with the multiplication facts you already know.

Common mistake: getting the family the wrong way round. From $5\times6=30$ the divisions are $30\div5=6$ and $30\div6=5$, never $5\div30$.

DIVISION UNDOES MULTIPLICATION

        x 4                 / 4
    3 ------> 12         12 ------> 3

FACT FAMILY for 3, 4 and 12:

    3 x 4 = 12      12 / 3 = 4
    4 x 3 = 12      12 / 4 = 3

So if you know your times tables, you already know division!
   7 x 6 = 42   ->   42 / 7 = 6   and   42 / 6 = 7
1
Worked Example

If $6\times4=24$, write the two matching division facts.

Solution
  • $24\div6=4$
  • $24\div4=6$
  • Answer: $24\div6=4$ and $24\div4=6$
2
Worked Example

Write the full fact family for $5$, $6$ and $30$.

Solution
  • $5\times6=30$, $\;6\times5=30$
  • $30\div5=6$, $\;30\div6=5$
  • Answer: those four facts
3
Worked Example

Use a times-table fact to find $42\div7$.

Solution
  • $7$ times what is $42$? $7\times6=42$.
  • So $42\div7=6$.
  • Answer: $6$
4
Worked Example

Find $56\div8$.

Solution
  • $8\times7=56$.
  • So $56\div8=7$.
  • Answer: $7$
5
Worked Example

Check whether $36\div6=6$ is correct.

Solution
  • Multiply back: $6\times6=36$.
  • It matches, so it is correct.
  • Answer: Yes, correct
6
Worked Example

Find $45\div9$ using your tables.

Solution
  • $9\times5=45$.
  • So $45\div9=5$.
  • Answer: $5$

Key Points

  • Multiplication and division are inverse (opposite) operations.
  • A fact family links three numbers, e.g. $3\times4=12$, $12\div3=4$, $12\div4=3$.
  • To divide, ask "what times the divisor gives the dividend?"
  • Knowing your times tables means you already know the division facts.
  • Check any division by multiplying the answer back.
  • Keep the family the right way round: from $5\times6=30$ you get $30\div5$ and $30\div6$.
Tap an option to check your answer0 / 4
Q1.Division is the opposite (inverse) of:
Explanation: Multiplication.
Q2.If $6\times4=24$, then $24\div6=$
Explanation: $4$.
Q3.To find $42\div7$, ask "$7$ times what is $42$?" The answer is:
Explanation: $6$.
Q4.You can check $36\div6=6$ by working out:
Explanation: $6\times6=36$.