Each day, students complete a warm-up that usually consists of spiraling the previous day's material, in addition to older material. Warm-up problems also sometimes extend lessons that students have encountered before to more unfamiliar contexts.
In this lesson, I walk kids through some basic equations, and show them that they are essentially creating 1's for coefficients. For example, 3x = 84. When you divide by 3 on both sides, you are creating a 1 (3 over 3).
We can apply this thinking to fractional coefficients. How can we create “1” with a fractional coefficient? (We need to multiply by the multiplicative inverse.) I use an analogy that the kids love… matchmaker. Make a perfect match – reciprocals are perfect matches, because when multiplied, they yield 1.
Then, we extend this to negative fractional coefficients as well… how can you create a POSITIVE 1 (a positive relationship with no yelling and arguing)… by using a negative number as the multiplicative inverse.
In the huddle in this lesson, we review a bunch of examples where kids make the perfect matches… and I tell the same joke over and over again until it sticks. J The kids generally love it, and also understand the concept of multiplicative inverse.
The homework includes questions related to this lesson, as well as spiraled review. I also provide answers to the problems on page 2.