**Day 1 Teaching**

Show 243 + 725 and say that we will use expanded column addition. First we partition numbers into 100s, 10s and 1s. Children partition the number using place value cards. Model layout and perform the addition. Repeat with 427 + 345 and other similar additions.

**Group Activities**

-- Work in 3s to partition pairs of 3-digit numbers, collect the 100s, 10s and 1s to find the total. Record the addition using the expanded layout.

-- Use place value cards and expanded addition to add pairs of 3-digit numbers, including those where the 1s >10.

**Day 2 Teaching**

Write 528 + 333. Who can show us how to solve this? Discuss solution given and the steps needed. Write 362 + 483. Point out how this time we need to add an extra 100 to the 100s column. Repeat with 473 + 253.

**Group Activities**

Use the ‘Expanded Elevens’ in-depth problem-solving investigation below as today’s group activity.

Or, use these activities:

-- Use place value cards and expanded addition to add pairs of 3-digit numbers, including those where the 1s >10.

-- Choose numbers from given sets to add using expanded addition. (10s >100).

**Day 3**

Write 318 + 235. Ask children how we estimate the answer. We round each number to the nearest 100. Write 200 + 300 = 500. Now find the answer using expanded addition and compare estimate. Repeat with 392 + 233, pointing out how 1 number rounds up and the other rounds down.

**Group Activities**

-- Work in 3s to partition pairs of 3-digit numbers, collect the 100s, 10s and 1s to find the total using expanded addition (10s >100).

-- Estimate which additions have totals </>800 (1s >10 OR 10s>100). Use expanded addition to find out.

-- Use place value cards to create additions where 1s>10 AND 10s> 100.