Jo often uses books to introduce the theme. This time she used a book with the intriguing title of "One is a snail, Ten is a Crab" By April Pulley Sayre and Jeff Sayre illustrated by Randy Cecil. It is a humorous and colourful way of looking at part-whole thinking.
The book is a "foot counting" book so it uses the number of feet on various animals or people to denotes the numeral - a snail is 1, a person is 2, a dog is 4, an insect is 6, a spider is 8 and a crab is 10 (including its pincers). So 40 can be 10 dogs (10 x 4) but also 6 insects and a dog (6 x 6 + 4)
She talked us through the book and then introduced the book to a group of children who had not previously read the book. She also had pictures of these animals and people prepared to use after the reading. The children were able to see that the snail was the number 1 because it only had one foot. Two was a person, then they were asked what numeral a number 3 was. The children counted 3 feet so they quickly saw that a snail (1) plus a person (2) made 3.
After introducing all the numbers up to 10, the book jumps up to the number 20. By the time Jo reached the page about 90 an immediate reply was given.
Jo posed a question about 4 feet - what pictures could we use? A child responded with "A dog" and was given the task of writing the numeral 4 underneath it. Jo then draws out their thinking by asking could 4 feet look any different? She shows a person. The children discussed, counted, checked and gave reasons, and wrote the numerals with Jo adding the addition and equals symbols.
By the end of the lesson the children have learnt how to make 6 in different ways.
A group of older children also worked with Jo using the same book.
We discussed ways in which we could extend the lesson for more able students to include skip counting and multiplication. We also looked at the NZ Maths site to become familiar with their resources, and Jo suggested using other books to introduce and reinforce number concepts and strategies.