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Showing posts from December, 2013

Prime Factorization and GCF

What a week! One snow day and 2 late starts so far! I just realized that I haven't written in almost 10 days.....I guess thinking about writing doesn't get the words on the page, huh?   Anyway, we worked on prime factorization at the end of last week, using both the factor tree method and the ladder method. Most of the students prefer the factor tree (I think that's because they've seen it before and feel comfortable with it), but a few like the ladder method. We've been using Prime Factorization Footloose to practice this skill; those who are finished have moved on to using the Factors and GCF Footloose cards. We have discussed GCF briefly, several times, and it is really a review for them (based on their pretest results); the biggest problem here is that they often skip factors when they list them, and miss the GCF because of missing factors.  Today, we're going to discuss using prime factorizations to find the GCF. I never learned this way when I was

Divisibility Fold It Up!

After pretesting our number theory and fractions chapter, I learned that very few students know the divisibility rules (many know 2, 5, and 10). So today we discussed the different rules and worked on our Divisibility "Fold It Ups." Click to download this freebie. The Fold It Up also includes the definitions of prime and composite, because the divisibility rules can help students to determine whether a number is prime or composite. After folding on the vertical line, students cut on the horizontal lines, and then wrote the rules on the inside. I've found that some students like to write on the reverse side of the flaps, while others like to write on the blank, "bottom" side, so I didn't tell them which part to write on, just that the rule had to be with the correct number! They also had to find a place to include our examples. It was interesting to see how students designed their Fold It Up. I made a few different examples of the inside, based o