3x2 Multiplication using the grid method

Topic guide

What this worksheet practises

This worksheet focuses on multiplying a three-digit number by a two-digit number using the grid method. This requires a slightly larger grid but uses exactly the same logical steps as simpler grid method problems.

Key method

The process is built on partitioning and organising your working:

1. Partition the three-digit number into hundreds, tens, and units.
2. Partition the two-digit number into tens and units.
3. Draw a grid with 3 columns and 2 rows (or vice versa). Place the partitioned numbers along the outside.
4. Multiply each row by each column to fill the six inner boxes.
5. Use column addition to find the total sum of the six boxes.

Worked example

Calculate 124 × 32

Step 1: Partition the numbers into 100, 20, 4 and 30, 2.

Step 2: Fill in the grid boxes.

• Top row (multiplying by 30): 100 × 30 = 3000, 20 × 30 = 600, 4 × 30 = 120
• Bottom row (multiplying by 2): 100 × 2 = 200, 20 × 2 = 40, 4 × 2 = 8

Step 3: Add all six results together.

3000 + 600 + 120 + 200 + 40 + 8 = 3968

The final answer is 3968.

Common mistakes to avoid

The most common errors occur during the final addition stage. With six numbers to add, it is very easy to misalign columns. Always write your numbers neatly in column format, ensuring the units line up perfectly on the right-hand side.

Useful tips

To make the addition step easier, try adding the rows horizontally first, then add the two row totals together vertically.