Split and addition of integers;
For example; 8+5 = 13, first split "5" into "2" and "3"; Then it is 8+2+3 =10;
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For example; 77+8 = 85, first split "8" into "3" and "5"; Then it is 77+3+5 = 85;
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Change an integer and subtract it.
For example, 26+ 18 = 44. If "18" is changed to "20-2", it is 26+20-2 = 44.
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For example; 387+983 = 1370, if "983" is changed to "1000- 17", it will be 387+1000-17 =/kloc-0.
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Dislocation number addition
For example, a unit plus ten digits is a unit;
5 1+ 15=66; This is calculated as follows: 5+ 1 6; 1+5 gets 6; Six pairs of spells in pairs
72+27=99; This is calculated as follows: 7+2 gets 9; 2+7 gets 9; Pairing 9 pairs of spells
63+36=99; This is calculated as follows: 6+3 gets 9; 3+6 gets 9; Pairing 9 pairs of spells
52+25=77; This is calculated as follows: 5+2 gets 7; 2+5 gets 7; Erqi combination
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For example, digits plus ten is ten;
78+87= 165; For example: 7+8 = 15, then add the numbers "1" and "5" to get 6, and put this "6" in the middle of "15" to get "165".
67+76 = 143, so: 6+7 = 13, then add the two numbers "1" and "3" to get 4, and put this "4" in "13".
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Subtraction mental arithmetic
Subtract integers and add them.
For example; 52-7 = 45, as follows: change "7" to "10-3"; Then, 52-10+3 = 45;
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Dislocation number subtraction
The difference between ten digits and single digits is multiplied by 9.
For example; 83-38=45; So, 8-3 = 5, 5x9 = 45.
For example; 97-79 = 18, so 9-7 = 2, 2x9 =18;
And so on.
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Multi-digit continuous subtraction
Such as 387-50-42-31= 264; Do a simple calculation first, 387-50 = 337, and then add 42 and 3 1 to get 73; Then, 337-73 can become 337-80+7 = 264.
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