Max Maths, Year 5, Learn together, Multiplying by a 2-digit number (1)

In the "Max Maths, Year 5, Learn Together" series, students are introduced to the concept of multiplying by a 2-digit number through a relatable scenario involving a delivery truck and mobile phones. The problem presented is to calculate the total number of mobile phones in a truck that carries 36 boxes, with each box containing 15 mobile phones. To solve this, students are encouraged to find the product of the two numbers involved: 36 and 15.

The lesson begins with an estimation technique, where students round each number to the nearest ten before multiplying. This provides an estimated product that gives a rough idea of what the actual answer might be. For example, 36 is rounded to 40 and 15 to 20, resulting in an estimated product of 800 when multiplied together. However, to find the exact number of mobile phones, two methods are suggested. The first method, known as the table method, involves breaking down the numbers into tens and ones, placing them into a table, and then multiplying each column and row. This method helps students visualise the multiplication process and understand that since both numbers were rounded up for the estimation, the actual product is expected to be less than the estimated 800.