At stake: two free tickets to the All-Star Game. And all you have to do is guess the correct number of jelly beans in a jar at the Planet Toys store. One particularly smart boy has an idea: Why guess when you can estimate? He plays a game with his buddy as they head over to the store on the bus. With four people per row, 10 rows, and a few folks standing in the aisle, he estimates that there are 43 people on the bus. "I didn't even need a pencil," he boasts. Knowing how to estimate is an essential skill that helps children determine approximate totals as well as check the reasonableness of their solutions to problems. Illustrated by S.D. Schindler.
Read the story together and ask your child or students to describe what is going on in each picture. Ask questions throughout the story, such as "What would you do to estimate how many people are on a bus?" and "How would you estimate the number of cars in a traffic jam?"
Discuss real life situations that require estimations. For example, ordering enough pizza for the whole family, or deciding how many errands can be done before ballet class or soccer practice.
Together, make up your own Betcha! game. Pick something that is difficult to count, such as people in a long line, cars in a parking lot, or cookies in a box. Help your child or students consider different strategies for making these estimates. Then check to see how close these estimates are to the real numbers.
You can use the MathStart books to introduce a concept as well as to reinforce a concept. An example would be "Betcha!" I usually read the book at the beginning of the year because we do estimation activities all year long. The kids can see how the kids in the story use different strategies for estimating. My students have to bring in their own estimation jars at least once a year. Everybody gets a chance. So it can be container of whatever – rocks, candies, straws. I’ve even had grass. They bring in all kinds of stuff. One kid brought in shark teeth from Florida, which was really neat. Sometimes I’ll give the winning estimator a pencil or a piece of candy, but mostly it’s about the glory.
from Richard Callan, Bunker Hill Elementary School, Indianapolis, IN
Playing with numbers—that's what this book from Murphy (The Best Vacation Ever, 1997, etc.) is all about. Part of the MathStart series, this entry introduces the art of estimation. Two boys are engaged in the project, one estimating, the other counting. Their ultimate goal is to try to figure out how many jelly beans are in a big glass jar and win tickets to a sporting event, but the storyline bows deeply to the emphasis on estimation as a process. As the boys head downtown to the toy store and the jelly beans, they estimate the number of people on the bus, the numbers of cars in a traffic jam, the total prices of goods in a window, all the while demonstrating both rounding off and how to count a small number and apply that to the great, uncounted whole through the use of multiplication, fractions, and simple geometry. Murphy's success is in beveling the sharp, unforgiving reputation of math and in showing how numbers can be toyed with. Readers may come away with the sense that they are not slaves to numbers—it's the other way around.Used with permission from Kirkus Reviews. Copyright ¬©1997, Kirkus Associates, LP. All rights reserved.
On their way to a store sponsoring a contest that involves guessing the number of jellybeans in a jar, two friends encounter situations that involve numerical determinations: e.g., how many people are on the bus, the number of cars in a traffic jam. One boy counts one by one to obtain the answers, whereas the other one uses simple techniques to come up with near estimations. The easy-to-read picture-book format with only one or two sentences per page will appeal to reluctant readers, and the boys' urban environment provides common situations to which many students will easily relate. The uncomplicated drawings show how the boy's brain is processing data and the skills he employs to arrive at an educated guess. The last two pages give suggestions and ideas for adults to help children further their understanding of the concept. A short list of similar concept books is included. This title will be especially useful for classroom use as it provides many possibilities for related activities.
—Stephani Hutchinson, Pioneer Elementary School. Sunnyside, WA
Used with permission from School Library Journal. Copyright Cahners Business Information, Inc.
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