Sunday, December 12, 2010

Need A Calculator?

I remember being taught to do math like this in school.  I wonder if it is still done in the elementary schools.  Probably not as it is not on the standardized tests.

Math test: Calculations for travelers

December 10, 2010 by McClatchy-Tribune

Calculating tips, mileage and foreign currency equivalents can make travelers break out in a cold sweat. How much to leave for a tip? How much is that hotel bill in dollars? No time for calculators or paper and pencil. You need to know right now.
Here are five questions to test your Travel Math Anxiety quotient.
The rules: No writing - you have to calculate in your head. Rounding off is allowed. Time yourself on how long it takes you to answer all the questions.

1. Your restaurant tab is $23, you want to leave a 20 percent tip. How much is the tip?
2. The exchange rate in London is 1 pound equals $1.54. If a box of candy costs 5 pounds, about how much is that in dollars?
3. You want to leave a 15 percent tip on a $14.77 tab. How much is the tip?
4. The exchange rate in Mexico is 12.20 pesos equals $1. If you buy a scarf for 95 pesos, about how much is that in dollars?
5. You have to drive 591 miles in four days and want to drive the same distance each day. About how many miles a day do you drive?

1. Figure out a 10 percent tip, $2.30, then double it, $4.60.
2. When calculating foreign exchange, always round off; in this case, use $1.50 instead of $1.54. That means that in dollars, everything is roughly 1 1/2 times the cost in pounds. So 5 pounds times 1.5 is $7.50.
3. Round the bill up to $15. Ten percent $1.50, and 5 percent is half that, 75 cents. Add those to get 15 percent or $2.25.
4. Think of 12.20 as 12. Divide 95 pesos by 12 and you get about $8. If you get confused, make yourself a cheat sheet: $10-122 pesos, $100-1,220 pesos.
5. Estimate: 591 is almost 600. And 600 divided by 4 is easy - 150. So you have to drive a bit less than that each day.

1 minute or less You're a genius - or a math teacher.
3 minutes or less: You should handle the money on vacation.
5 minutes or not at all: Let someone else handle the cash.


Anonymous said...

Your wondering is correct. Math is not taught like this anymore. Concrete concepts and real-life experiences are no longer the forefront to math education.

Other than the the standardized tests, the elementary mathematics 'phenomena' is inquiry-based learning. One program that focuses on inquiry-based learning is Investigations/TERC. TERC focuses on the higher level aspects in elementary math education but forgets about the knowledge and comprehensive components. (My acronym for TERC-Tricky Erroneous Ridiculous Crap)

The teachers hate it, the students do not like it and are confused. They ask the teachers, can we learn a different way? This could be the reason why so many children are coming to junior and senior high schools not knowing basic arithmetic.

ChiTown Girl said...

See, this is how I KNOW I was a straight up GEEK as a kid. I used to ADORE doing these kinds of problems! The highlight of my freshman Honors Alg. class was that we had to complete a workbook of about 1,000 problems over the course of the first semester. I walked around with that book 24/7! To this day, my mother still talks about it! (My youngest niece has inherited my love for all things math, and for as long as I can remember, she's asked my sister to buy her math workbooks every time they were at a store. She always has one with her, so my mom always teasing her about being just like her auntie.)

ChiTown Girl said...

BTW, I finished in under a minute. ;-)