Decimals - Multiply Decimals by 10, 100 and 1,000 - Presentation

The lesson on multiplying decimals by 10, 100, and 1,000 aims to deepen students' understanding of place value and the effects of multiplication on decimal numbers. Students begin by using a place value grid to visualise the process, taking a number like 3.24 and multiplying it by 10, 100, and 1,000 to see how the value of each digit changes and shifts within the grid. The lesson illustrates that when a decimal is multiplied by these factors, the digits move to the left by one, two, or three places respectively. This simple yet effective method reinforces the concept that multiplying by 10, 100, or 1,000 increases the value of a number and shifts its decimal point to the right.

Further activities include multiplying different decimal numbers like 3.67 and 56.6 by 10, 100, and 1,000, encouraging students to observe patterns and understand the consistent nature of place value shifts during multiplication. A reasoning task prompts students to create their own numbers with up to three decimal places and explore the results of multiplication on a Gattegno chart, helping to visualise the movement of digits across different place values. Through these exercises, students can see that each digit moves up a row but remains in the same column, thereby solidifying their grasp of the concept. The lesson also encourages discussion on the significance of zero in numbers and the importance of maintaining its position during multiplication to preserve the correct value of the number.