Written Multiplication & Division
Write and calculate mathematical statements for multiplication and division using known tables, including two-digit × one-digit, using mental and progressing to formal written methods
What a learner can do afterwards
- Calculate 23 × 4 using partitioning (20 × 4 + 3 × 4)
- Calculate 96 ÷ 8 using known table facts
- Begin to use a formal written layout for short multiplication
The lesson
You already know your times tables. Now you can use them on bigger numbers, like 23 × 4 or 96 ÷ 8. The trick for multiplying is to split the big number into tens and ones, work out each piece, then add the pieces back together.
To work out 23 × 4, split 23 into 20 and 3. First, 20 × 4 = 80. Then, 3 × 4 = 12. Add the two parts: 80 + 12 = 92. So 23 × 4 = 92.
Grown-ups often write multiplication in columns, like a small tower of numbers. You multiply the ones digit first, write down the ones part of the answer, and carry any tens into the next column. It looks different, but it does the same job as splitting the number.
Division uses your table facts too. To work out 96 ÷ 8, ask: what times 8 makes 96? You know 8 × 12 = 96, so 96 ÷ 8 = 12. If that feels too big, split it: 96 is 80 + 16. 80 ÷ 8 = 10 and 16 ÷ 8 = 2, so 10 + 2 = 12.
Split big numbers into tens and ones, multiply or divide each part with your tables, then put the parts back together.
Watch it
Where it sits
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.