によって Cameron Smmith 3年前.
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Expanded form: *adding by place value 100+20+3 100+20+3 _________ 200+40+6 = 246 Left to Right: *add beginning with the first digits, using their appropriate value 123+123 200 40 6 ______ 246 Friendly numbers: *first adding the numbers that make ten 62+28 2+8= 10 60+20=80 10+80=90 Trading off: *transferring a key amount from one side of the plus sign to the other to create a more simplistic addition 75+28 (+2)73+30 = 103 Scratch: * rounding numbers in an equation up or down to create more easeful adding; typically done in factors of five or ten, adding & subtracting the difference accordingly to account for the difference 4+6+9+11=20 5+5+10+10=20 Lattice: *using a box to separate the digits of the equation, only adding single digits, then adding the columns 2 5 +4 8 _______ 0 1 6 3 7 3