I always hated word problems, but when my granddaughter in third grade asked for my help with her homework, I figured how hard could that be? Well, too hard for a pretty smart young lady and her grandmother, I guess.
Here are the facts:
- A four-pack of lightbulbs [sic] costs $1.07
- A box of tissues costs $0.99
- A four-pack of batteries costs $1.99
- Transparent tape costs $0.84
- Ballpoint pen costs $0.24
- VCR Tape (How old is this worksheet?) costs $2.79
Now for the first problem:
"John must buy supplies for his company. He needs five lightbulbs, four boxes of tissues, and six rolls of transparent tape. How much money will he need for these supplies?"
First, there are too many variables in this problem for any 8-year-old (or grandmother of eight) to remember. But I think, let's break it down into steps.
I circle the first fact, "five lightbulbs." But they come in packs of four. So are we supposed to assume we have to buy two packs to get five of them? Well, Home Depot would so I go with that approach. Let's teach the child how things work in the shopping world. So that's 2 X $1.07 = $2.14. My granddaughter kind of knows how to do this, although she multiples the dollar by two, the zero tens by two, and the seven cents by two and then adds them all together. OK, not super efficient but she gets the concept and the correct answer.
But wait. Maybe they mean literally five lightbulbs and no more. In that case, we have to find out how much each light bulb costs, so now we are dividing. Our new problem is $1.07/4 = $0.2675. That's a tough one because she really doesn't know what to do with the remainder, and neither do I. I guess we could round up but I'm not sure what they call that these days. We decide to add $0.27 to the $1.07. She can do this easily, so now we have $1.34.
Now we have two possible answers for the first step. "Which one do we use, Gramma?" she asks. I tell her to put that question aside until we complete all of the steps.
We circle the box of tissues costing $0.99 and note that John needs four of them. Super easy. That's $0.99 X 4 = $3.96. Once again, she does the thing with the zeros, but this is something she's practiced in school, so it makes sense to her.
Now we have the issue of the transparent tape. Again, not too bad. John needs six rolls of tape. The tape costs $0.84, so we just have to work out $0.84 X 6 = $5.04. She misaligns her zeros, and it's time for dinner. So in the interests of getting this done because it is one of five word problems and there is also a sheet full of regular problems to complete, I tell her to figure out 84 X 6 and then turn it into money. I know - my bad. But I can see we will have a problem with the final step.
We just have to add up the answers from the first three steps so John knows how much money he needs to buy those items. But which answer do we choose from step one? I tell her there could be two correct answers, but she refuses to add $2.14 + $3.96 + $5.04 for one answer AND $1.34 + $3.96 + $5.04 for a second possibility. Besides, dinner is burning.
Once again, I suggest that she wait until her mother gets home. I'm not sure she knows how to divide $4.00 by $0.24 in the next problem to figure out how many pens Ms. Larson can buy. I tell her she could think about it as how many pens costing a quarter could she buy for $4.00. She knows right away that it's 16, but argues that the problem doesn't tell her to estimate.
I notice that the next problem involves buying videotape for the school pageant, and I throw in the towel when she asks me what a VHS tape is. I'm pretty this worksheet is much older than my granddaughter.
It's taken me over 700 words to get this far in describing a third grader's math homework. Now I remember why I hated every math problem that began, "A train is traveling one direction at 60 miles/hour..." No way am I going to spend another minute on this assignment. If she really wants to analyze how much things will cost her in life, she has to accept that no one will sell her one light bulb.