Index: | |
Unit plans | . |
*Adding and Subtracting |
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Multiplying and dividing |
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Basic Operations | Basic Operations Cards |
add | subtract | easier... 51 + 23= 50 + 1 + 20 + 3 |
(can be tricky if unit to be subtracted is larger) easier ... 54 - 12= (50 - 10 = 40) (4 - 2 = 2) 40 + 2 = harder ... 54 - 16 = (40 - 10 = 30) (14 - 6 = 8) 30 + 8 = |
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add | subtract |
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easier .... 55 + 23= 55 + 20 = 75 75 + 3 = |
(no difference if unit being subtracted is larger) smaller unit being subtracted ... 55 - 23 = 55 - 20 = 35 35 - 3 = larger unit being sutbtracted ... 55 - 26= 55 - 20 = 35 35 - 6 = |
addition | subtraction |
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29 + 13= 30 + 10 + 3= 43 43 - 1 = |
(can be tricky especially if the unit being subtracted is larger) easier .... 57 - 25= (50 - 20 = 30) (7 - 5 = 2) 30 + 2 = harder ... 57 - 28 = (40 - 20 = 20) (17 - 8 = 9) 20 + 9 = |
addition | subtraction |
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28 + 14 = 28 + 10 + 4 |
(size of the units makes no difference ... a real bonus esp for LA children)
smaller unit .... 28 - 14 = 28 - 10 = 18 28 - 4 = larger unit ... 28 - 19 = 28 - 10 = 18 18 - 9 = |
addition | subtraction |
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easier ... 27 + 29 = 25 + 2 + 25 + 4 |
harder ... (double is less apparent) 53 - 26 = 50 -25 =25 (3 - 1 = 2) 25 + 2 = |
addition | subtraction |
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easier .... 14 + 7 = 21 harder ... 15 + 9 = (14 + 7 = 21) (1 + 2 = 3) 21 + 3 = |
easier ... 28 - 7 = 21 hard - can children cope with inverting? ... 27 - 9 = (28 - 7 = 21) (+1 + 2 = +3) 21 - 3 = 18 |