### Teaching and Group Activities for Understanding

**Day 1 Teaching**

Use a 20-bead frame to show 5 + 2 on lower bar, hiding all other beads behind the whiteboard. What is 5 add 2? Slide top 10 beads across and discuss how we now have 15 add 2. Tell children that we only needed to know one number fact (5 + 2) to find 15 + 2. Recall ‘Spider’ from earlier in term, for adding 10. Refer to 1-100 grid.

Use the bead frame to show further additions and subtractions. If we know what 5 - 2 is, then we can use this fact to find 15 – 2.**Group Activities**Use the ‘Cross Additions’ in-depth problem-solving investigation below as today’s group activity.

Or, use these activities:

-- Solve additions and subtractions using number facts.

-- Apply knowledge of number facts to add and subtract.

**Day 2 Teaching**

Write 35 + 3, 27 - 5, 30 + 5, 46 + 6, 27 - 7, 56 + 3, 99 – 3. Draw out using number fact 5 + 3 = 8 for first question. Stick card under heading Number fact. How about 30 + 5? Use place value! Stick card under a heading Place value. Discuss which use PV, which use a number fact. Sort cards into 2 sets. Answer some.

**Group Activities**

-- Sort calculations according to the strategy used to solve them.

-- Investigate equality using an on-screen interactivity.