In my estimation...1510

Estimation is not always for jelly beans guessing contests. No, no. Estimation is an important skill to have when doing addition, subtraction, multiplication and division. There are many strategies to help students estimate. Why do this? It can be a useful first step in order to get us on the right track as well as check our final answer.

What is important in estimation is knowing what you want to estimate...amount,lentgth, volume, an answer to a multiplication problem...once you know what you're looking for you can employ one of many strategies to determine your estimated answer.

Let us begin with answers to multiplication or addition problems...a superior strategy is rounding. If you are given a set of funky numbers to add or multiply you can use rounding to make them more friendly. So, say you've been given 23, 31, 19 and 15 to add. They are snarly numbers that don't add real nice at first glance. So you round them to the nearest 10...like 23 is nearest to 20 and 31 is nearest to 30. Those were easy but what about that mean looking 15? The general rule is to round UP. If we use that rule then the 15 would be thought of as 20. The 19 is snuggled right up next to 20 so that would also be 20 and we could then easily add 20+30+ 20+ 20 which equals 90.

In some cases, the estimated answer is good enough- like when you're at a big box store and throwing items willy-nilly in your cart and you have 100 bucks in cash and need to estimate if you have exceeded your wallet's capacity. If those numbers were prices I'd be able to stop because I'd know that I had enough money but I'd better high-tail it to the check out because one more clearance bargain might push me over the edge.

If they were numbers that represented diamonds, rubies, emeralds and opals, I'd want to know exactly how many precious gems I had in my possession. So I'd check it with my calculator and see that all told I had 88 gems and if I lend them to the Queen of England, I'd better get all 88 back.



So say you want to estimate the number of donuts to bring into work each day for a week and you remember than the last time that donuts were brought in there were 34, 27, 29,36 and 31 donuts consumed. You could use the clustering technique to estimate how many you should bring- all those numbers sort of cluster around a number...which looks like 30 to me. And since the donuts were brought in for five days you could multiply 30 times 5 and determine that bringing in 150 donuts will probably see you through.

Estimation, as I said, is not just for jelly bean guessing games, it is for donuts too.

Measurement and the young student- 1512

Measuring marigolds might just be a great idea when introducing the concept of measurement to young students. I really like the idea of using non-standard units of measure so the marigold could be the ruler for that matter! But seriously,folks, I do agree that young students will grasp the concept of measuring much better if you begin with things they know. Have them use their feet or their hands to measure their desk or chair. In my observations I have seen teachers use things like ice-cream scoops to measure the height of the kids in the class, marking off each student on a wall chart made of a super stack of construction paper scoops. I liked that one a lot. The kids will all get it and will probably tell their parents for the next year how many scoops high they are.
Teaching measurement skills will work so well with estimation skills that I can already see a load of activities to try out...take a guess how many spaghetti noodles tall you are! Guess how many Ritz crackers are in a stack as high as your chair! Take a stab at how many juice boxes it will take to fill an aquarium! The best part would be actually carrying out these crazy stunts to see how close they came to the correct answer.

The idea is to get the making reference points for size, weight and volume before they begin to practice with standard units of measure. So having access to various containers to see how many of this fit into that will be important. They can also begin to compare their own measurement with that of other students and adults. It would be interesting to have the students estimate how tall older students might be in 5th grade, 8th grade and 12 grade and then go and actually measure a group of students to find out if they came close. I think I'm getting an overload of ideas for this topic and that, as Martha Stewart would say, "is a good thing." Yes, it is.

By the way, if you estimated that Martha is tall you'd have been right- she is in fact, 5'9" tall or you could estimate her at around 23 McDonald's french fries (which in turn I'm estimating at 3 inches...)

Once students are getting comfortable with standard units of measure like feet, yards, pounds (or grams, centimeters and liters if you are so inclined), you could use these estimating skills in other subjects as well. Make a treasure hunt for social studies and have them find things that measure certain amounts...like find an object that would have been on the Great Plains that would have weighed 2000 lbs or something that would have been a foot tall standing or half that walking...the possibilities are endless.

Can you guess which animal I was looking for in the questions above?  Thanks to all the references you've made over the years it should be easy to figure that the Buffalo is taller than 12 inches so it must have been the one that is around 2000 pounds.

Of course, I can't leave without giving you another video that should appeal to young students as they grapple with the concept of THE FOOT. Enjoy.