Each term in the sum differs by 6, so that the [tex]n[/tex]th term is determined by [tex]4+6(n-1)[/tex]. The last term is 70, so there are
[tex]4+6(n-1)=70\implies n=12[/tex]
terms in the sum. If
[tex]S=4+10+\cdots+64+70[/tex]
then it's also true that
[tex]S=70+64+\cdots+10+4[/tex]
and joining the sums gives us
[tex]2S=(4+70)+(10+64)+\cdots+(64+10)+(70+4)[/tex]
[tex]2S=12\cdot74[/tex]
[tex]S=\dfrac{12\cdot74}2\implies\boxed{S=444}[/tex]
