Problem Solving Strategies

Guess Check

When you are solving a problem, sometimes, it is a whole lot easier to guess the answer to the problem and then check it.

HOW TO:

So, you need to know HOW TO guess and check your answer. That is EASY (there's that word again, EASY!!!). OK, here is an example problem, DON'T WORRY, I am going to help you solve it!!

You have 4 (four) pizzas that are divided into 12 pieces each. You have 23 kids that want pizza. How many pieces of pizza does each of the kids have?

First you know that you have four pizza's that have about 10 pieces of pizza in each. As you know 4x10=40. So you have about 40 pieces of pizza. You have about 20 kids that you need to feed pizza. 40 divided by 20=2. You know that each kid may have about 2 pieces of pizza.

Now that you know that each child will have about 2 pieces of pizza, you have to check your answer. 4x12=48. You have 48 pieces of pizza. 48 divided by 23 (because you have 23 kids)=2 remainder of 2 pieces of pizza. Each child will be able to eat 2 pieces of pizza.

In this problem, using the Guess and Check strategy turned out to be the correct answer, but I'll have you know that there are some problems that when you use the Guess and Check strategy, the answer is different then what it would be if you actually solved it without rounding. Was that easy? Of course it was. Do you think you can handle a problem by yourself? I know that you can. Don't freak out, you can solve this problem using the Guess and Check strategy, but then you can check your answer!! This one will be a little harder though. Here goes nothing!!

Twenty-five dolphins and killer whales perform at Sea Circus. There are 13 more dolphins than killer whales. How many of each animal are there?

First of all, you have to make a guess. How bout 15 dolphins +10 killer whales=25. No no, there has to be 13 more dolphins, there is only 5 between there. Let's see how about 20 dolphins+5 killer whales. No, between those is 15, so I am much closer, but not close enough! I bet 19 dolphins + 6 killer whales will do the trick!! Yes, yes that is correct, we have solved this problem by using GUESS AND CHECK!! We did it!!! There are 19 dolphins and 6 killer whales performing at the Sea Circus!!

Click here for more examples of guess and check and for other problem solving strategies visit Math Stories!