To review the concept of subtraction, read Roll Over or There Were Ten in the Bed, or sing the song Ten in the Bed from the Song Lyrics sheet. For each part, ask a student to act out with links what is happening, and have each student write the related subtraction sentence on a slate.
Now read the first three pages of Quack and Count to the students, using 6 links in one color and 1 link in another to make a chain that illustrates the text on the first three pages (for example, 7 – = 6, 7 – 6 = 1, 6 + 1 = 7, 1 + 6 = 7). If you cannot obtain the book mentioned, have a volunteer tell a story that involves subtraction by taking sets away. Model as described above. Then write the fact family.
When the students seem comfortable with this procedure, distribute links of two colors to pairs of children and have them take turns making chains, taking away the indicated group of links, and writing equations as you finish the story or as additional volunteers give subtraction problems. This activity will help the students focus on the relation of subtraction to addition. When you get to the last page, have children model 7 – 7 and write the related addition and subtraction sentences (7 – 7 = 0, 0 + 7 = 7, 7 + 0 = 7) on slates.
Then call the class together and ask students to share what they think a fact family is. Invite one of the children to make a chain with 3 links of one color and 3 of another, and write the related addition and subtraction sentences (there will be only one of each). Finally, ask the students to write a fact family for one of the chains they made. This could be added to their portfolios to document their growth in understanding.
