### Teaching and Group Activities for Understanding

**Day 1 Teaching**

Show children a bead bar with tags showing multiples of 10. Count on in 10s from zero. Point at different numbers and count on from these. What is the number after 45? Agree 46. 46 is 1 more. What comes before 45? 44 is 1 less. Repeat with 37 and other 2-digit numbers on a 0–100 beaded line. Show the numbers on a 1–100 grid.

**Group Activities**

-- Give clues for children to find numbers on a 1–100 grid. Describe each number’s position.

-- Make a 2-digit number and mark it on a 0–100 beaded line.

**Day 2 Teaching**

Write the calculations: 23 + 1, 34 + 1, 29 + 1, 99 + 1, 24 – 1, 67 – 1, 60 – 1, 80 – 1. For each, locate the first number on the 0–100 beaded line, count on/back one bead, label where they land, and draw a hop labelled + 1/– 1. Complete additions and subtractions on the board. Then use them to complete the sentences: ___ is more than ___, and ___ is less than ___.

**Group Activities**

Use the ‘Stop the bus!’ in-depth problem-solving activity below as today’s group activity.

Or, use these activities:

-- Make a 2-digit number and find one more/one less than this number.

-- Find numbers to make a blank number statement true.