Conjectures/Justification Session 5

Outcomes for Conjectures/Justifications When you want the students to take informal knowledge and make it formal. Proof that it will always work It is truly based on mathematical rules

Big Ideas about Conjectures Read individually Share at your table Talk about it as a large group

Review the introduction and editing of conjectures in the classroom. Read pages Post one “big idea” from the reading on chart paper to discuss after the break.

Conjectures Go through a series of T & F number sentences Look at the series, can someone tell me a mathematical rule to help us solve these math problems

Conjecture examples 27-0 Can someone suggest a mathematical rule for this series How do we know this is true

Watch video clip 3.2 and 3.3 Generating a Conjecture Using Number Sentences

Justification Kids can prove to you that their answer is mathematically correct Examples of justification must be proven by using concrete examples Students will begin to say “I know this” Use justification to make students understand a rule, why it works, and to prove that the algorithm will always work

Handout Big Ideas of Justification – Work through these problems and provide proof for each one. – Present justifications to the rest of the group

Watch video clip 5.3, 5.1 and 5.8 Watch students make conjectures and justify

Convention What we just tell them -all symbols +, -, /, x (start talking about them when they appear in context) -definitions-when it comes up in conversation “I counted along the outside”, mathematicians call this perimeter -when they learn notations don’t use words anymore, use “add” instead of “plus”

Accountibility Developing Teachers Eyes and Ears (3-2-1) Do in class before you leave and hand in 3-2-1