大象传媒

MultiplicationMultiplication by three digit whole numbers

A number can be multiplied to two decimal places by a single-digit whole number or by multiples of 10, 100 and 1000 using a standard written format and without a calculator.

Part of Application of MathsNumeracy skills

Multiplication by three digit whole numbers

Multiplying with a three digit whole number

To multiply \(237\) by \(324\) without using a calculator, you can set it out like this:

Diagram of a multiplication sum.
Diagram of a multiplication sum.
Diagram of a multiplication sum.
  1. The first two lines of the calculation use the same procedure as that of above.
  2. In the third line we are multiplying by \(300\) (three hundreds). As we are multiplying by hundreds both the tens and unit digit will always be zero.
  3. In a similar procedure to above:- \(3 \times 7 = 21\) put the \(1\) in the hundreds column and carry the \(2\) to the thousands column.
  4. \(3 \times 3 = 9\); add the carried \(2\) to get \(11\), put \(1\) in the thousands column and carry \(1\) to the tens of thousands column.
  5. \(3 \times 2 = 6\) add the carried \(1\) to get \(7\) so put the \(7\) in the tens of thousands column.
  6. Add \(948\) and \(4740\) and \(71100\).

Therefore \(237 \times 324 = 76788\)

A similar method is followed for multiplying using four digits.

Diagram of a multiplication sum.
Diagram of a multiplication sum.
Diagram of a multiplication sum.
Diagram of a multiplication sum.
Diagram of a multiplication sum.

\(5607 \times 3061 = 17163027\)

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