### Teaching and Group Activities for Understanding

**Day 1 Teaching**

Write 426 + 257 + 582 and 275 + 446 + 385. Estimate the answer to each addition. Point out that lots of the numbers round up so looking at the first digit only does not give a good estimate. Model using compact addition for the first addition. Compare with children’s estimates. Children use compact addition for 2nd addition, then for 726 + 457 + 582.**Group Activities**

-- Whole class investigation: Apply compact addition skills to add trios (or pairs) of 3-digit numbers, aiming for given target totals.

**Day 2 Teaching**

Show a complete compact addition for £3.55 + £2.76. Ask children to explain to their partners how this was done, talking through each stage. Discuss each stage. Show books with price labels: £4.79, £5.49, £5.25, £4.65, £4.29. Children collaborate to find totals of pairs for under £10.**Group Activities**

-- Add pairs of amounts of money using expanded and then compact addition.

-- Choose the most efficient method to add pairs of 3-digit amounts (some money).

-- Apply compact addition skills to add trios of 3-digit amounts of money.