Those dreaded word problems. What is it about word problems that put such fear in our hearts? My daughter said it yesterday. She is taking Algebra this year and they are doing word problems. Her comment about her friend was that she found word problems difficult. She said to me, “But Mom, she does them just find if I set them up for her.” ‘Set them up!’ That’s the trick. My child is translating the words into the correct equation, then her friend has no trouble doing the calculation. But the math skill being taught with word problems is doing the translation, doing the set up.

Word problems have got to be the only school math that most resembles real life. Except in real life we don’t always have all the information we need or we have extra numbers that don’t help. And we certainly don’t have an answer sheet or text to show us how to set up the equation. I have heard that more elementary schools are doing word problems. I think this is great. But it is still not enough. Parents need to help.

As parents we need to involve our kids in the real life word problems that we do everyday. Take dinner for example. You have a 2.43 pound roast that requires a 1/2 hour per pound to cook and you want to eat at 6:30 pm. At what time should you start cooking it? Did you add time for the meat to rest after cooking before eating it? Did you add preparation time at the beginning for getting it ready to cook? Now at what time do you start in order to eat by 6:30 pm. Here’s another example. You are comparing two items at the store. The 16 oz product sells for $2.79 and the 12 oz product sells for $1.99. Which is the better buy? Or better yet, you are painting a room. The room is 12 x 10 with 8 foot ceilings. A gallon of paint covers 100 sq. feet. How many gallons of paint will you need to put on two coats. These are all word problems that we deal with everyday. Get your child involved with helping you solve your word problems.

Did I get you thinking? These are typical real life word problems. There is no answer sheet, no hint as to how to solve them, no equation to use. Did you figure them out? Did you use a calculator. These are problems I just get a rough estimate for. I have found an estimate to be good enough. Since I only need a rough estimate, I usually do these problems in my head.

Take the dinner problem. I need 15 minutes prep time and 15 minutes rest time. The 2.43 pound roast that requires a 1/2 hour per pound to cook, will take approximately 1 hour and 15 minutes. Hence I want to start at at 4:45 pm and have the roast in the oven by 5 pm. Do you need the exact minute? I don’t think so. Now if you are launching a rocket, then you might want to be a bit more accurate.

For our next example, we are comparing two items at the store. The 16 oz product sells for $2.79 and the 12 oz product sells for $1.99. Which is the better buy? I do this in my head by using rounded numbers. Notice that 16 oz and 12 oz are both divisible by four. The price on the 16 oz is also divisible by 4, approximately .$70 for 4 oz. Multiply the 4 oz price by 3 to get the equivalent 12 oz price, $2.10. Now you can see that the $1.99 price for 12 oz. is better than the $2.79 price for 16 oz. My equation is

($2.80/4) * 3 = $2.10 <-- the 16 oz product price for 12 ounces of product.

Could I have divide by 16 and multiplied by 12? Sure, but I find that harder to do in my head. I would need a calculator. Would the results have been different? No, not unless I calculated wrong which is possible with larger numbers. Did I need to calculate it to the penny? No! I just want a rough idea which was the better buy. If my estimating comes out close, then I buy the size I want. This is practical math. This is the kind of math our children will be doing as adults. This is the kind of math they don’t teach in our schools.

What if the numbers hadn’t been so nice? What if we were comparing 15 oz at $2.76 and 8 oz at $1.99? I would round up the 15 oz to 16 and use a price of $3.00. Divide $3.00 in half and that’s your 8 oz price at $1.50. By this guesstimate I would buy the 15 oz, instead of the 8oz.. Am I right? Let’s use our calculator.

($2.76/15oz) * 8oz = $1.48 < this is the actual cost for 8 oz at the 15 oz price

My guess that the 15 oz product was the better buy is correct. Don’t be afraid to estimate. Even when calculating the dinner tip, I estimate by taking 20% of the dinner bill rounded down to the nearest dollar or to nearest ten dollars. Then adjust it as you like.

The last example is painting a room. The room’s wall square footage is 12 * 10 * 8 = 960 sq. feet. If a gallon of paint only covers 100 sq. feet, I would buy another brand. From my calculations, you will need 20 gallons of paint. At $20 per gallon, $400 is an expensive paint job. From my personal experience, a room that size should only need 4 gallons. How would you know that? Before you buy, check the paint can for the estimated square foot coverage and then buy all the paint you need at once. Matching paint color later after you have the room is half done, is nearly impossible. I know this too from personal experience.