### Teaching and Group Activities for Understanding

**Day 1 Teaching**

Today we’re going to use two familiar resources that both represent or show numbers from 0.01 to 1 – the bead bar and the 100 square. Use tags to mark the tenths on a bead bar; count along in tenths, then hundredths. Show a blank 100 square with just 0.01, 0.02, and 0.03 marked. Discuss what number will be at the end of the top row/ in the square under that/ in the bottom right corner. Mark other numbers on the square. What size steps are we counting in going down the grid?**Group Activities**

-- Use counting on and back in tenths or hundredths to fill in missing adjacent numbers in a 0.01–1 square.

-- Fill in a row and column of a 0.01–1 square; identify the numbers in ‘crosses’ drawn on the 0.01–1 square.

-- Work backwards to identify starting numbers when adding/subtracting tenths and hundredths.

**Day 2 Teaching**

Display the 0.01–1 square. Count in steps of 0.01 from 0.3 to 0.4, then back, then in steps of 0.1 from 0.05 to 0.95 and back. Write 0.35 + 0.4 and model, using the 0.01–1 square: start at 0.35, count on 0.4. Which digit changes? Repeat for 0.35 – 0.04 and 0.35 – 0.4.

**Group Activities**

Use the ‘Decimals in a row’ in-depth problem-solving investigation below as today’s group activity.

Or, use these activities:

-- Play a game adding and subtracting hundredths on a completed or blank 0.01–1 square.

**Day 3 Teaching**

Write: *A snail has crawled 2.34m. It crawls 4cm more. How far has it crawled now?* What calculation do we need to do? Which digit will change when we add 4cm? Why? Establish that 4cm is the same as 4/100 of a metre or 0.04m. Write the number sentence: 2.34m + 4cm = 2.38cm. Repeat with another word problem to add a multiple of 10cm.**Group Activities**

-- Convert distances in m to cm, or vice versa, to help solve measures problems.

-- Solving measurement problems, recognise which digit will change when a number of m or cm is added.