Max Maths, Year 5, Learn together, Multiplying by a 2-digit number (2)

The Max Maths Year 5 curriculum introduces a method for multiplying by a 2-digit number, using the example of calculating the product of 36 and 15. The first approach is to break down the multiplication into simpler steps, multiplying the number 36 by each digit of the number 15 separately and then adding up the results. Initially, 36 is multiplied by the ones digit (5), yielding 180. Next, 36 is multiplied by the tens digit (1), which gives 360 after accounting for the place value. Adding these partial products together—180 and 360—results in the final answer of 540. This method confirms that there are 540 mobile phones in the truck, which is notably less than the estimated 800.

Method 2, known as the column method, offers another systematic approach to the same problem. The process begins by multiplying the top number (36) by the ones place digit of the bottom number (5), resulting in 180. The next step involves multiplying the top number by the tens place digit of the bottom number (1), remembering to add a zero in the ones place to maintain the correct place value, which gives 360. The final step is to add these two results together—180 and 360—to get the total product of 540. This method also confirms the quantity of mobile phones in the truck to be 540, aligning with the earlier calculation and demonstrating that the result is consistent and less than the initial estimate of 800.