5 - 3 = 2 INV: cars in a car park, counters to 5 - 2 = 3 represent cars 2 + 3 = 5 INV: same situation, numbers 5,3,2 3 + 2 = 5 INV: linear layout of counters 5 = 2 + 3 5 = 3 + 2 These transformations are not new to the students. 5. "They are all correct, but one INV: cars in a car park, counters to tells our story best. Which represent cars one?” INV: same situation, numbers 5,3,2 INV: linear layout of counters 5 - 3 = 2 is selected INV: symbolic representation of situation All chant 'subtraction can tell us about take away' 6. "Now represent: there are five From the teacher: red cars and there are three DoV2: different image; RoC: 'remove' or blue cars." 'compare' numbers DoV3: different coloured counters were Pupils told to use a row of 5 used and the irrelevance of this was and a row of 3: discussed. ●●●●● INV: cars in a car park, counters to ●●● represent cars Colours of the counters seen INV: numbers 5, 3 and 2 as irrelevant (non defining). INV: linear layout of counters INV: symbolic representation of situation 7. "Looking at this picture what From the pupils: Pupils show is the difference between the DoV 5: the ways the difference is worked different ways to number of red cars and the out and expressed; RoC counting on, using express the number of blue cars. Tell the number facts, comparing numbers, one to 'difference': person next to you." one matching is 2 less than 5 “3 and 5 is 2 more T draws a part-part-whole From the class discussion: than 3” diagram to represent the DoV 6: the way the cars are mentioned; The difference situation with the cars, and RoC: the difference between the cars 5 and 3 red “between overlays that onto a picture of and the cars, later it is asked as is 2” blue counters: difference between the is a smaller number of blue “3 and the number than 5” counters number of red counters, the and the number of blue cars number of 'how many more red cars ...?' red cars, From the teacher: DoV 7: the ways in which the
INV: cars in a car park, counters to represent cars INV: same situation, numbers 5,3,2 INV: linear layout of counters 5 - 3 = 2 5 - 2 = 3 2 + 3 = 5 3 + 2 = 5 5 = 2 + 3 5 = 3 + 2 These transformations are not new to the students. 5. "They are all correct, but one tells our story best. Which one?” 5 - 3 = 2 is selected All chant 'subtraction can tell us about take away' INV: cars in a car park, counters to represent cars INV: same situation, numbers 5,3,2 INV: linear layout of counters INV: symbolic representation of situation 6. "Now represent: there are five red cars and there are three blue cars." Pupils told to use a row of 5 and a row of 3: ●●●●● ●●● Colours of the counters seen as irrelevant (non defining). From the teacher: DoV2: different image; RoC: 'remove' or 'compare' numbers DoV3: different coloured counters were used and the irrelevance of this was discussed. INV: cars in a car park, counters to represent cars INV: numbers 5, 3 and 2 INV: linear layout of counters INV: symbolic representation of situation 7. "Looking at this picture what is the difference between the number of red cars and the number of blue cars. Tell the person next to you." T draws a part-part-whole diagram to represent the situation with the cars, and overlays that onto a picture of counters: From the pupils: DoV 5: the ways the difference is worked out and expressed; RoC counting on, using number facts, comparing numbers, one to one matching From the class discussion: DoV 6: the way the cars are mentioned; RoC: the difference between the red cars and the blue cars, later it is asked as difference between the number of blue counters and the number of red counters, the number of blue cars and the number of red cars, 'how many more red cars ...?' From the teacher: DoV 7: the ways in which the Pupils show different ways to express the 'difference': “3 is 2 less than 5 and 5 is 2 more than 3” The difference “between 5 and 3 is 2” “3 is a smaller number than 5”
variation_mastery_video_analysis_bsrlm_2017.docx