“I’m never going to use this math in real life!” complained Joseph while he was doing his algebra homework. Joseph could see his parents using arithmetic; adding, subtracting, multiplying, and dividing for daily activities. Now that he's in algebra, he thinks he has passed the type of math that people use in the “real world.” He couldn’t be more wrong. Joseph’s parents decided to notice whenever they were using algebra so they could mention it to him. That evening they had their first opportunity.
What is Algebra?
Algebra is a precise and concise mathematical language to describe situations with one, or more, variable. Think of how often our lives have variables in them!
An Evening Using Algebra
Joseph's parents were going to a restaurant for dinner and they had a budget of $80. They had to fill the gas tank. They needed at least 15 gallons of gas to get to the restaurant. The price of gas depended on where and when they buy it (variable). How much could they afford to order off the menu (variable) and still have enough money for tip and tax?
First they had to define the problem. That took strong mathematical reasoning skills. They asked Joseph for help. Joseph suggested labeling everything as follows.
Gas price is Y
Amount they could order off the menu is X
Tip 20 % of X
Tax is 7% of X
Total budget must not exceed $80
Then they had to create the equation. Like word problems, real life scenarios require complex problem solving skills. Joseph helped again.
80 ≥ X (.2) + X (.07) + 15Y + X
Solve for X
They bought gas first for $1.95 per gallon.
They put that in for Y.
80 ≥ X (.2) + X (.07) + 15 (1.95) + X
80 ≥ X (.2) + X (.07) + 29.25 + X
Then they simplified by subtracting 29.25 from both sides of the equation getting,
50.75 ≥ X (.2) + X (.07) + X
When they looked at the menu they plugged in different menu items for X to make their equation true. First they tried $30
50.75 ≥ X (.2) + X (.07) + X
50.75 ≥30 (.2) + 30 (.07) + 30
50.75 ≥6 + 2.1 +30
50.75 ≥ 38.10
They realized, yes, they could order $30 of food from the menu but Joseph wanted a $12 appetizer. Could they order $42 of food from the menu?
$38.10 + 12.00= $50.10 which is less than their budget so it might seem like they could. But using algebra they realized that it might not work because they would pay tax and tip based on the new total
They plugged in $42 for X. 50.75 ≥X (.2) + X (.07) + X
50.75 ≥ 42 (.2) + 42 (.07) + 42
50.75 ≥ 8.4 + 2.94 + 42
50.75 ≥ 53.34 is false
50.75 ≤ 53. 34 They could NOT buy the $12 appetizer!
Joseph and his parents started noticing when they were using algebra more and more, Joseph became more enthusiastic about his algebra class. And of course Mathnasium of Parker was there to help Joseph when he struggled.
This article was written by and owned by Cuttlefish Copywriting, www.cuttlefishcopywriting.com . It is copyright protected. Mathnasium of Parker has permission to use it. Other Mathnasium locations should contact Heather at [email protected] before using it.