Number
Multiplying two digits by one
Multiply a two-digit number by a single digit.
Nobody learns a times table that goes up to 23. What you do instead is break the two-digit number into the part that is tens and the part that is ones, multiply each of those, and add the two answers back together. Splitting a number up like this is called partitioning, and it turns a sum you have never seen into two you already know.
Tens are just times tables with a zero
20 × 4 is not a new fact. It is 2 × 4 = 8 with the answer standing one column further to the left, which makes it 80. Once the tens are that easy, every two-digit multiplication is a table fact, another table fact, and one addition.
Worked example
Work out 23 × 4.
Split 23 into 20 and 3.
The tens and the ones can be multiplied separately without changing the answer.
Try it together
Now let us do 36 × 3 together.
Split the 36 into its tens and its ones, and take them one at a time.
1.First the tens. What is 30 × 3?
Have a go
Have a go on your own: 58 × 4 = ?
Hint: Fifty fours and eight fours, added together.
Ready to practise?
Eight questions on what you have just read. Nothing is timed, and you can play as many times as you like.