MA 1.07One More and One Less

1. 1

   Lay out the Number Rods as a stair. Place rod 4 apart and have the child name it.

2. 2

   Lay rod 5 beside rod 4, lined up at the red end. Point to the extra section: 'Five is one more than four.'

3. 3

   Lay rod 3 on the other side of rod 4: 'Three is one less than four.' Have the child count the sections to check.

4. 4

   Repeat with other rods. The guide names a rod; the child brings the rods for one more and one less.

5. 5

   In a later lesson, use Cards and Counters. Lay out card 6 with its counters. Add one counter: 'Six and one more is seven.' The child finds card 7.

6. 6

   Take the counter away again: 'One less than seven is six.'

7. 7

   The guide names a number; the child shows one more and one less with counters and finds both cards.

What catches the child’s eye

• The single section that sticks out past the shorter rod
• One counter added or taken away, changing the whole number

Extensions, easiest to hardest

1. Without the material, the child answers 'What is one more than eight?' and checks with the rods.
2. Lay three cards in a row: one less, the number, one more.
3. Find one more and one less for 11–19 once the Teen Boards are known.