The charming read aloud book One Is a Snail, Ten Is a Crab provides inspiration to students to expand their number sense and practice their use of addition, subtraction, multiplication, and division.

NOTE: The following activities allude to One Is a Snail, Ten Is a Crab, which assigns numbers to animals based on how many legs they have. Students should read the book before attempting the activities. You can find a copy of One Is a Snail, Ten Is a Crab by April Pulley Sayre and Jeff Sayre at your local library or online. Below is a table listing all animals which appear in that book.

Animal		Number of Legs
	snail	1
	person	2
	dog	4
	insect	6
	spider	8
	crab	10

Activities on this page:

• How Many Feet Are on the Beach?
• What's on the Beach?
• What Did Diego Count?
• Mental Math Riddles

How Many Feet Are on the Beach?

Students are given pictures of various animals on a beach. Students utilize their grouping skills to find how many feet are on the beach.

Materials:

• a copy of One Is a Snail, Ten Is a Crab
• paper and pencil

Directions:

Examine each picture. Find how many of each animal are on the beach. Write an equation to help you find the total number of feet that are on the beach.

Exercises:

1. 
2. 
3. 
4. 
5. 

What's on the Beach?

Students create their own beach pictures based to fit a given number.

Materials:

• a copy of One Is a Snail, Ten Is a Crab
• paper and pencil
• markers, crayons, or colored pencils

Directions:

Draw your own beach scene! First, find a combination of animals that will put the given number of feet on the beach. Then draw your beach scene. Use it to challenge your fellow students.

Exercises:

1. 47
2. 59
3. 62
4. 71
5. 88
6. 94
7. 103
8. 122
9. 159
10. 176

What Did Diego Count?

Materials:

• a copy of One Is a Snail, Ten Is a Crab
• paper and pencil
• markers, crayons, or colored pencils

Directions:

Diego was swimming at the beach and saw lots of different animals. He counted all their feet, but didn't count how many of each animal he saw. Using the information below, can you figure out how many of each animal Diego saw? Explain each of your answers with a picture, a sentence, and an equation.

NOTE: Each of the following problems have multiple solutions. For an extra challenge, can you find all the solutions for each problem?

Exercises:

1. Diego saw lots of people and dogs on the beach. He counted 46 feet. How many people and dogs did Diego see?
2. Diego saw lots of insects and snails on the beach. He counted 63 feet. How many insects and snails did Diego see?
3. Diego saw lots of dogs and spiders on the beach. He counted 92 feet. How many dogs and spiders did Diego see?
4. Diego saw lots of crabs and people on the beach. He counted 112 feet. How many crabs and people did Diego see?
5. Diego saw lots of insects and crabs on the beach. He counted 136 feet. How many insects and crabs did Diego see?
6. Diego saw lots of insects and spiders on the beach. He counted 116 feet. How many insects and spiders did Diego see?
7. Diego saw lats of people, dogs, and snails. He counted 23 feet. How many people, dogs, and snails did Diego see?

Mental Math Riddles

Materials:

• a copy of One Is a Snail, Ten Is a Crab
• paper and pencil

Directions:

Read each of the following riddles. Try to keep track of the number of feet in your head (without paper and pencil). When you reach the end of the riddle, write your final total on a piece of paper. Then re-read the riddle and write number sentences that fit the riddle to help you keep track of the number of feet. Use your written total to check your mental total. Are they the same?

Riddles:

1. Start with the number of feet of 8 people. Add the number of feet of 3 dogs. Then subtract the number of feet of an insect. Next, add the number of feet of 3 crabs. Also add the number of feet of a spider. Now subtract the number of feet of 7 snails.
2. Start with the number of feet of 7 dogs. Subtract the number of feet of 3 snails. Then add the number of feet of 3 spiders. Next, subtact the number of feet of 3 crabs. Finally, add the number of feet of 8 insects.
3. Start with the number of feet of 9 spiders. Add the number of feet of 4 crabs and 4 people. Next, subtract the number of feet of 11 snails. Also subtract the number of feet of 5 dogs. Now, the add number of legs of 2 people. Finally, add the number of legs of 6 insects and a dog.
4. Start with the number of feet of 15 people and 6 spiders. Subtract the number of legs of 3 crabs and a snail. Now add the number of legs of 11 spiders. Next, add the number of feet of 7 insects minus the number of feet of 3 people. Finally, subtract the number of feet of 8 people and 7 dogs.

This work placed into the public domain by the Riverbend Community Math Center.