Long multiplication, short and long division, and multiplying and dividing decimals by place value, all by hand.
What you will learn
- Multiply a three-digit number by a two-digit number
- Divide by a one-digit or two-digit number
- Multiply and divide decimals by place value
- Decide what to do with a remainder
Long multiplication
Split the second number into tens and ones.
Multiply by each part, then add the two rows. The row for the tens starts with a zero in the ones column, because the tens digit is worth ten times as much.
- 463 × 27
- 463 × 7 = 3241
- 463 × 20 = 9260 (a zero in the ones column first)
- 3241 + 9260 = 12501
With money, work in pence: 24 tickets at £3.15 is 24 × 315p = 7560p = £75.60. The change from £100 is £100 − £75.60 = £24.40.
The grid method gives the same rows: write 463 as 400 + 60 + 3, multiply each part by 20 and by 7, then add all six answers.
The rest of this lesson and its 8 practice questions are locked.
In this lesson
- Long multiplication
- Short and long division
- Decimals by place value
- Remainders in context
- Try it: Check by multiplying back
8 practice questions, marked as you go; about 25 minutes in all.
In this unit: Non-calculator methods
Everything Paper 1 asks you to do by hand: written multiplication and division, fractions and percentages, estimating and checking, exact answers, and multi-step problems without a calculator.
- Written multiplication and division
- Fractions and percentages by hand
- Estimating and checking
- Exact answers
- Non-calculator problem solving