Tocalculatethesumofallintegersfrom1to100,wecanusetheformulaforthesumofanarithmeticseries.Here'sadetailedbreakdown:
∪△∪ Step1:UnderstandtheProblem
˙ω˙ Weareaskedtofindthesumofallintegersfrom1to100,inclusive.Thisformsanarithmeticsequencewhere:
≥ω≤ Thefirstterm$a_1=1$
Thelastterm$a_n=100$
o(╯□╰)o Thecommondifference$d=1$
╯^╰ Thenumberofterms$n=100$
≥▽≤ Step2:UsetheArithmeticSeriesSumFormula
Theformulaforthesum$S_n$ofthefirst$n$termsofanarithmeticsequenceis:
$$
S_n=\frac{n}{2}\times(a_1+a_n)
$$
ˇ▽ˇ Substitutetheknownvaluesintotheformula:
$n=100$
$a_1=1$
$a_n=100$
$$
(*?↓˙*) S_{100}=\frac{100}{2}\times(1+100)
$$
$$
˙▽˙ S_{100}=50\times101
$$
$$
˙﹏˙ S_{100}=5050
$$
 ̄□ ̄|| Step3:VerificationviaPairingMethod
Anintuitivewaytoverifythisresultisbypairingterms:
$1+100=101$
$2+99=101$
≥▂≤ $3+98=101$
...
Thereare$\frac{100}{2}=50$suchpairs.
So,totalsum:
$$
(#`′)凸 50\times101=5050
$$
>▽< Thisconfirmsourcalculation.
FinalAnswer
$$
\boxed{5050}
$$
