整数的运算（Integer operation）.doc

整数的运算（Integer operation） Integer operation I. what is addition and what is subtraction? 1. Addition: the operation of combining two numbers into a number. Subtraction: two known numbers and one number, for the other addend operation. 2, the name of each part 5 + 2 =7 10-4 =6 Addend addend + = and = difference parts reduction (addition and subtraction are reciprocal operations!) 3, the vertical Bisuan Vertical writing to digital alignment calculation, carry carry to write, to write the abdication of abdication point. * Please use the vertical calculation 15+27=, II, 82-35=, 56+24-43= The 42-29= and 83-25=, 73+19-58= and 90-38+29= 4, summary: The two digit and two digit Bisuan rules: 1. Same digit alignment. Add from one position to another. A total of ten, 1 to ten. Two digits minus two digit Bisuan rules: 1. Same digit alignment. Reduce from position. There are not enough places to go from ten to 1, plus ten to reduce the number of persons. 5. Deduction: multi number and multi number add and subtract. Method of adding: Digital alignment, bit plus, full ten forward, one into one. Subtraction method: Digital alignment, bit reduction, the same digit is not enough, the forward one borrow 1, when ten, the same number together to reduce. * Please use the vertical calculation. 487+256=, II, 246+187= The 216+528= 398+199= and 340-90= 429-186=. 6, addition and subtraction law of operations and operational properties The operation law of addition: the commutative law of addition: the sum of two numbers, and they exchange addend position unchanged. By the letters a, B represent the two number, can be written as a+b=b+a Addition law: add three numbers, add the first two numbers, add the third numbers, or add the first two numbers, add the first number, and keep the same. By the letters a, B, C represent three number, can be written as a+b+c= (a+b) +c=a+ (b+c) The nature of operations of subtraction: the reduction of two consecutive numbers from a number is equivalent to subtrac