backwards in 399 add i.e. half of numbers with the expectation that → appropriate 400 and then 5.6, double as children’s knowledge of place decimals and subtract 1. 3.4. value is secured, they become percentages. Sums and ready to approach a formal differences compact method. of decimals, i.e. 6.5 + 2.7 Stage 6: Continue to Bridging Ensure all Columnar addition (formal written Pupils to be encouraged to consider practice through children are method): mental strategies first. previous decimals, i.e. confident The concept of exchange is Formal columnar: skills. 0.8 + 0.35 = recalling introduced through continued use 25 Count 0.8 + 0.2 + basic facts of practical equipment +47 forwards and 0.15 to 20 and (manipulatives). backwards in empty number deriving Teachers model: simple lines. facts using have two tens and five ones, “I fractions, Partitioning place value. need adding to four tens 25 decimals and using near Make links and seven ones.” +47 percentages. doubles, i.e. between add five ones to seven ones, “I 2 2.5 + 2.6 = 5 + decimals, which gives me twelve ones.” 1 0.1 fractions and exchange ten of my twelve “I Reorder percentages. ones for a ten counter.” decimals, i.e. add my three tens and four “I 25 4.7 + 5.6 0.7 tens to make seven tens.” – +47 4.7 I have tens …as… – “Altogether, 2 0.7 + 5.6 = 4 + and two ones.” 5.6. Teachers similarly advance to 1 model the addition of two 3-digit numbers, e.g. 25 +47
backwards in appropriate decimals and percentages. 399 → add 400 and then subtract 1. i.e. half of 5.6, double 3.4. Sums and differences of decimals, i.e. 6.5 + 2.7 numbers with the expectation that as children’s knowledge of place value is secured, they become ready to approach a formal compact method. Stage 6: Continue to practice previous skills. Count forwards and backwards in simple fractions, decimals and percentages. Bridging through decimals, i.e. 0.8 + 0.35 = 0.8 + 0.2 + 0.15 empty number lines. Partitioning using near doubles, i.e. 2.5 + 2.6 = 5 + 0.1 Reorder decimals, i.e. 4.7 + 5.6 – 0.7 …as… 4.7 – 0.7 + 5.6 = 4 + 5.6. Ensure all children are confident recalling basic facts to 20 and deriving facts using place value. Make links between decimals, fractions and percentages. Columnar addition (formal written method): The concept of exchange is introduced through continued use of practical equipment (manipulatives). Teachers model: “I have two tens and five ones, need adding to four tens and seven ones.” “I add five ones to seven ones, which gives me twelve ones.” “I exchange ten of my twelve ones for a ten counter.” “I add my three tens and four tens to make seven tens.” “Altogether, I have tens and two ones.” Teachers similarly advance to model the addition of two 3-digit numbers, e.g. Pupils to be encouraged to consider mental strategies first. Formal columnar: 25 +47 25 +47 2 1 25 +47 2 1 25 +47
Oxfordshire%20Draft%20Calculation%20Policy%20-%20Updated%20October%202015.docx