### Teaching and Group Activities for Understanding

**Day 1 Teaching**

Quick practice doubling 1-digit numbers and multiples of 10 less than 50.

Model doubling of 2-digit numbers, using a jotting to show partitioning and recombining.**Further Teaching with Y3**

Further doubling of 2-digit numbers, using place value cards to support, e.g. for 34, 46 and 57.**Group Activities: T with Y4**

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

Or, use these activities:

Y3 -- Doubling 2-digit numbers: either to 50, or numbers greater than 50.

Y4 -- Doubling any 2-digit number.

**Day 2 Teaching**

Model halving of 2-digit numbers by partitioning and recombining, including examples with odd tens digit.**Further Teaching with Y4**

Revisit halving and doubling multiples of 100. Introduce doubling and halving of 3-digit numbers by partitioning and recombining.**Group Activities: T with Y3**

Y3 -- Halving 2-digit numbers, including money amounts; check by doubling.

Y4 -- Doubling and halving 3-digit numbers; reasoning about strategies.

**Day 3 Teaching**

Quick practice halving multiples of 10 (to 90).

Model halving odd numbers (2-digts) using partitioning and recombining.**Further Teaching with Y3**

Find half of 3, 5, 7, 9 then 5, 25, 45 and 65; reason about patterns.**Group Activities: T with Y4**

Y3 -- Find halves, describing patterns of halves in different number sequences: 2-digit numbers.

Y4 -- Find halves, describing patterns of halves in different number sequences: 2- and 3-digit numbers.