This sequence begins with a focus on developing students’ counting skills to work with numbers beyond 10, then continues on to build early place value understanding as students investigate teen numbers. The key understanding of unitising is introduced as students use a group of 10 and some more ones to represent numbers 11 to 19. This task continues to use the book One is a Snail, Ten is a Crab. It introduces students to the patterns of our place-value system and the significance of 10. The key understanding of unitising is introduced by asking students to represent teen numbers using one crab, which is the same as using 1 ten. In doing so, students move from using 10 ones to 1 ten. One is a snail, two is a person, three is a snail and a person, four is a dog, five is a dog and a snail! This ingenious counting book is all about feet. Not the kind with inches. The kind with toes, or paws, or claws. “1 is a snail. 2 is a person. 3 is a person and a snail.” The four-footed dog plus a snail equals five. The eight –footed spider plus a snail equals nine. Ten? Why, ten is a crab! And that means 20 is two crabs. Forty is four crabs, or ten dogs or…you get the picture. And so will kids. No doubt they’ll be eagerly creating their own pedimentary equations in no time.” Summary: This is a creative book on counting. Sayre uses animals’ legs to teach children to count while also teaching children how many legs different animals have.

The concept of using small skills to create a foundation for larger skills is done effectively in this book, using familiar animals and human attributes to allow the reader to see the math and math tools in any setting.

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have used 10 as a group previously, such as participating in tasks that use models such as tens frames. The mathematical focus of the story and the use of everyday items that students recognize can be recreated in the classroom using a variety of tools. Any manipulative from food to marbles can be combined from smaller sets to larger sets, modeling the process within the book. Brief Book Summary: This book is entirely about counting, and uses unique and creative ways of showing children how to do so. The book begins by showing the reader that a snail has one foot, so they begin there at one. Then it continues that two is a person because a person has two feet. Three is a person and a snail. Four is a dog because they have four legs. Five is a dog and a snail. Six is an insect. Seven is an insect and a snail. Eight is a spider. Nine is a spider and a snail. Ten is a crab. The book then continues to count by ten’s up to one hundred using various things to count with for instance, “twenty is two crabs”, and “thirty is three crabs or ten people and a crab.”

After reading the book explain to students that they (or their pair) will each get to pull a number from the bag and make that number in 2 ways using the counting feet from the story. have an understanding of the composition of numbers; for exampl, 7 can be made by combining 1 and 6. The humorous nature of the story is presented in multiple settings with crabs in a pyramid, crabs in a conga line, and crabs headed to the shore with their inner tubes. While they only have two small eyes and a simple mouth this provides ample expression as one crab is left behind with ten spiders, looking rather uncomfortable. Prior to reading, warm up with some number recognition and partitioning questions. “Play Guess my Number” with the hundreds board by choosing a “mystery number” in your mind and having students ask questions to narrow the search for the mystery number (Does it have a 2 in the ones column? etc.). Reverse the game and give clues that help them narrow the search for another number (for example: My number has an even number in the tens column, or My number is 4 more than tidy number, or My number is made up of a two digits that are the same, etc.)

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The numbers are printed in a font size that is significantly larger than the text, cueing the reader to their importance. The use of multiple examples for the larger numbers also provides multiple avenues to understand how smaller groups are combined to form one larger group. The element of humor makes the learning fun and introduces math in a context that is meant to be silly. With one hundred snails finishing the story the original character is brought full circle and the connection between one and one hundred firmly established.

When you are counting by feet then 1 is a snail and 2 is a person and 4 is a dog! This book uses the number of feet on various animals to be the units by which numbers can be expressed. So for example: “40” can be 10 dogs (10 x 4) or 20 people (20 x 2) or 6 insects and a dog (6 x 6 + 4). The book is a humorous and colourful illustration of part-whole thinking. In providing numerous ways to conceive of numbers, the text and the illustrations give the reader critical repetition. “”30 is three crabs…. or ten people and a crab.” This is a really clever book which has strong cross curricular links with numeracy. The author is using feet/footprints as a counting tool. This is a great book which can be used across all primary year groups. The author carries on until 10 like this and then moves on to counting up to 100 (100 is ten crabs!) Lots of activities can stem from this book and can span a whole range of maths topics from basic counting to addition to algebra. E.g Are there any other ways we could make 100? (ie. 9 crabs, 1 dog and 6 snails) I tend to agree more with Kristin Harris because I really felt that this book was creative and imaginative especially for a math book. I can remember reading very boring counting books, but this one would have actually kept my attention. I also agree that the illustrations are humorous and colorful. Throughout the book I would catch myself stopping and really taking the pictures in. I think that children would love this book.Prior to this lesson you can have created copymasters of your own children’s drawings of the “units” (snail, person, dog, insect, crab) by asking someone to draw one of each and then reproducing them on a photocopier to create sheets of units or you can use the copymaster of clip art “units” or you can have each child do their own drawings for the activity.