Teaching and Group Activities for Understanding
Day 1 Teaching
Use counting stick to count in 0.01s from 2.45 to 2.55 and back. Label 2.5 with a Post-it. Write 2.52 – 0.03. Count back from 2.52 to 2.49. Sketch a jotting to show how we ‘bridge’ 2.5. Repeat for 2.47 + 0.07. Mark the centre as 2, then count in 0.01s from 1.95 to 2.05 and back. Use the counting stick and a jotting to work out 2.02 – 0.05.
-- Game to add and subtract multiples of 0.01 crossing through multiples of 1 and 0.1 using a number line.
-- Repeatedly add 0.06, then subtract 0.07. Challenge to repeatedly add multiples of 0.01 to end on a given number.
Day 2 Teaching
Show 3 DVDs labelled £10.49, £14.79, £12.25. Estimate total cost by rounding. Model compact addition to find total cost. Remind children to leave a line below numbers being added so we can write extra digits. Finish and compare with estimate. Repeat for 3 other prices.
-- Add three amounts of money, aligning digits correctly. Estimate totals first.
-- Add two amounts of money, aligning digits correctly. Estimate totals first.
Write three amounts with a total within a given range.
Day 3 Teaching
Use the distance that snails crawl to generate decimal additions. Children round each distance to nearest metre to estimate the total. Model column addition, showing how to align decimal points.
Use the ‘Adapt Four of the Best’ in-depth problem-solving investigation below as today’s group activity.
Or, use these activities:
-- Add and round three distances in metres (2dp) crawled by snails.
-- Shuffle given digit cards to make additions of distances in metres with 2dp, round and find the total.