AV and JV have been filling missing or lost math processes.
JV has been working through the process of learning how to factor LCM and GCD beginning with Lower El fraction lessons and working on multiples.
He has moved through the multiples of 1-10 up to 100 (2 x 41 = 82) in each column. This large chart is often a culmination event for Lower Elementary students. It is often mounted and displayed for reference in the classroom for a few days. JV has continued to work on the chart but in reverse. The numbers 1 – 100 are written on each line. The child then ads the different ways to arrive at this answer. (12 = 1 x 12, 2 x 6, 3 x 4). The other day we redid this chart and did it using factors (12 = 2 squared x 3). AV was roped in because I knew he had never had the lesson. They asked to do more.
Today we took out our 10 x 10 grid of 100 and circled the 2 and then marked the multiples of 2. We continued with the other numbers’ multiples. (For those of you keeping Montessori score, the colored pencils are the bead cabinet colors with gray substituted for the white of sevens.)
We punched holes on the grid to show only composite (not prime) numbers – had to fix one at the end as it is neither but was punched out. The ones that could not be punched were removed by means of nail scissors or a fine x-acto blade. This work was mounted on a piece of brightly
colored paper. Then I invited them to observe and write their observations.
This process is known as the Sieve of Eratosthenes. Finding relationships among
numbers is of great joy to this age. The discovery of the secrete patterns and sharing their observations provides such a sense of power over the world of numbers.