- (5 min) Mental Math
- What is 1/5 of 35? [7]
- What is 1/20 of 100? [5]
- What is 1/9 of 36? [4]
- What is 23% of 200? [46]
- What is 12% of 300? [36]

- (5 min) RATES

Rates involve numbers and units expressed as fractions. They are expressed with a "/" or "____" which is read as "per". Rates usually measure speed, with time as the denominator, but sometimes there are other units instead.Sally types 45 words 45 words/min 45 words per minute ----- min I drove 30 miles 30 miles/hr 30 miles per hour ----- hour Pistachios cost five $5/lb. $5 dollars per pound -- lb

Both numbers and units can be multiplied and canceled when using rates. (All problems in this section assume a constant rate.) I drove 30 miles per hour. How far did I drive in 4 hours?30 miles x 4 hours = 120 miles ----- hour

I drove 30 miles per hour. How fast did I drive per minute?30 miles x 1 hour = 1 mile ----- ---------- - ------- hour 60 minutes 2 minutes

I drove 1/2 mile in 1 minute! You know you have it set up right if the hours cancel. This is wrong:30 miles x 60 minutes 180 mile-minutes ----- ---------- = ------------ hour 1 hour hour

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- PROPORTIONS

Now lets set up some equations:

If 6 bananas cost $1.20, how much will 4 bananas cost? Set it up as two equivalent fractions. Make sure that the thing you want to find (x) is in the numerator and solve for x. Make sure that you have the same units on top and the same units on the bottom. In this problem we will put money on top and bananas on the bottom:$1.20 = X -------- --------- 6 bananas 4 bananas Solve: 4 bananas x $1.20 = X ----------------- 6 bananas X = 80 cents

Here is another way to do the same problem using the idea from algebra that we do the same thing to both sides of an equivalence. Here we setup the bananas on the left and the money on the right.6 bananas are $1.20 | | | | V V (take 2/3) (take 2/3) | | | | V V 4 bananas are ??? (80 cents)

- (Remainder of class) In-class exercise

- Hand out homework as students successfully complete the in-class exercise.
- Competitions

The first competition (Functions and Relations) stresses setting up equations from word problems. Each equation is worth 2 points, and each right answer is worth 1 point.The second competition is an organized approach to guess and check. The first one has a table to work in and the first guess made, just to get the kids started. The last one needs the kids to set up their own table.