Montessori Elementary Homeschool Blog - with documentation of our infant Montessori, toddler Montessori, and primary Montessori experiences; as well as preparation for the upcoming adolescent Montessori homeschool years.

Tuesday, December 11, 2012

Multiplying Sum by a Sum

Legoboy loved this work intensely - for about 3 weeks. Then he's done. He found the shortcut of adding up the quantities within parentheses and then multiplying, so we had to move on to unknown quantities to keep him practicing the proper procedure!

The idea is to start with lower numbers, with bead bars within one set of parentheses and number cards in a second set of parentheses; then show proper procedure for multiplying each bead bar by each "command card", finding partial answers and later putting them all together into the final product. We turn over the multipliers (commands) not being used, so that we isolate just the one individual being used at the moment.

Talk about good habit-forming right from the beginning and before EVER doing the abstractly!

So. He LOVED the work. And he loves drawing. But for some reason, he always rushed through the few drawings he made of his work onto graph paper. Go figure! Here is a sample - he started off well except for parentheses ;) As Grandma says: Funny boy!
(ordinarily the partial answers are placed underneath their corresponding bead work - not to the right as he shows it here - but he likes to have all of his work of this sort fit onto one piece of paper when possible). He still had the final product on a different piece of paper which he then tucked away somewhere I can't find to show you all! He does that with his favorite work until he is ready to share. I can't complain! At least he wrote the numerical answer at the bottom :)

Sample of 2-sum by 3-sum

1 unit by a sum of 2 addends, then switch it around. 

sum by a sum - basic presentation :) 

No comments:

Post a Comment