Presentation of Written Calculation Methods Ysgol Owen Jones Presentation of Written Calculation Methods

Aims of Policy To raise awareness in the methods used in school of written calculations To illustrate the progression of calculation methods that children will meet. To explore activities of reasoning and problem solving that children will meet.

Addition Children encourage to visualise the number system through using Numicon, objects and number lines 8 + 5 = 13 Use of number lines – numbered and then blank 34+23=57

Year 3 – empty number lines with larger numbers 58+86 = 124 +50 +4 +4 86 116 120 124 49 + 73 = 122 73+50 =123 -1 =122

Horizontal Partitioning 67+24=91 60+20 = 80 7 + 4 = 11 =91

Vertical Methods 76 76 76 + 47 + 47 + 47 ____ _____ _______ 76 76 76 + 47 + 47 + 47 ____ _____ _______ 110 13 12 1 3 13 110 _____ ______ 123 123 Decimal point is in line

Subtraction Early methods the same except counting backwards. Decompositon 25 – 13 using Numicon or base 10 25 -16

Formal Subtraction Decompostion 56 145 11 8 6 _________ 5 6 5

Multiplication Practical activities grouping sets Counting in 2s 5s 10s Use of Numicon Repeated addition on a number line 4 x 6 = 6 + 6 + 6 + 6 Model with arrays

Grid method Short multiplication TU x U 23 x 8 20 3 8 160 24 = 160 24 20 3 8 160 24 = 160 24 ------- 184

Long multiplication 560 60 16 ______ 2736 70 2 30 2100 60 70 2 30 2100 60 8 560 16 2100 560 60 16 ______ 2736

Division Practically Repeated Division 72 3 3 ) 72 -30 10 42 10 - 30 72 3 3 ) 72 -30 10 42 10 - 30 12 2 6 6 2 0 Answer 24