Решебник по математике 5 класс Ерина Виленкин рабочая тетрадь Часть 1, 2 Часть 1 | Страница 31

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\[\boxed{\mathbf{4}.}\]

\[\boxed{\mathbf{5}.}\]

\[\textbf{а)}\ A(3)\]

\[\textbf{б)}\ E(10)\]

\[\textbf{в)}\ F(12)\]

\[\textbf{г)}\ K(8)\]

\[\textbf{д)}\ B(16)\]

\[\textbf{е)}\ P(14)\]

\[\boxed{\mathbf{6}.}\]

\[12 + 7 = 19\]

\[8 + 0 = 0\]

\[\boxed{\mathbf{7}.}\]

\[(300 + 85) + 15 =\]

\[= 300 + (85 + 15) =\]

\[= 300 + 100 = 400\]

\[(73 + 48) + 27 =\]

\[= (73 + 27) + 48 = 100 + 48 =\]

\[= 148\]

\[328 + (50 + 522) =\]

\[= (328 + 522) + 50 =\]

\[= 850 + 50 = 900\]

\[999 + (1 + 600) =\]

\[= (999 + 1) + 600 =\]

\[= 1000 + 600 = 1600\]

\[485 + 648 + 515 =\]

\[= (485 + 515) + 648 =\]

\[= 1000 + 648 = 1648\]

\[421 + 526 + 274 =\]

\[= (526 + 274) + 421 =\]

\[= 800 + 421 = 1221\]

\[348 + 222 + 52 + 78 =\]

\[= (348 + 52) + (222 + 78) =\]

\[= 400 + 300 = 700\]

\[524 + 307 + 1476 + 393 =\]

\[= (524 + 1476) + (307 + 393) =\]

\[= 2000 + 700 = 2700\]

\[\boxed{\mathbf{8}.}\]

\[\textbf{а)}\ 237 + 548 + 623 + 312 =\]

\[= (237 + 623) + (548 + 312) =\]

\[= 860 + 560 = 1420\]

\[\textbf{б)}\ 315 + 842 + 228 + 425 =\]

\[= (315 + 425) + (842 + 228) =\]

\[= 740 + 1070 = 1810\]

\[\textbf{в)}\ 296 + (422 + 504) =\]

\[= (296 + 504) + 422 =\]

\[= 800 + 422 = 1222\]