Стр.70 Часть 2 ГДЗ Башмаков Нефедова 4 класс (Математика)
Выполни вычисления.
а) $$68\,027+3\,784$$
б) $$71\,029-6\,385$$
в) $$3\,789+6\,450-9\,230$$
$$17\,329+28\,371$$
$$34\,600-15\,480$$
$$41\,315-7\,480+165$$
$$342\,608+16\,492$$
$$428\,095-74\,807$$
$$605\,402-84\,917+15\,470$$
$$852+609\,247$$
$$120\,470-63\,542$$
$$320\,317+94\,754-960$$
г) $$6\,024\cdot71$$
д) $$24\,875\cdot53$$
е) $$1\,862\cdot260$$
ж) $$1\,687\cdot307$$
$$2\,065\cdot45$$
$$12\,290\cdot36$$
$$2\,016\cdot450$$
$$2\,571\cdot504$$
$$5\,068\cdot310$$
$$30\,640\cdot74$$
$$4\,692\cdot181$$
$$3\,027\cdot206$$
$$4\,207\cdot330$$
$$20\,904\cdot85$$
$$2\,790\cdot234$$
$$7\,142\cdot109$$Найди неизвестное число.
а) $$2\,109+\text{х}=10\,109$$
в) $$m-(647-47)=3\,800$$
$$\text{у}-954=39\,000$$
$$60\,000-(n+12\,000)=37\,000$$
$$85\,300-z=7\,300$$
$$(5\,682-p)+18=1\,700$$
$$k+5\,962=225\,962$$
$$(r-1\,908)-92=4\,630$$
б) $$202\cdot u=8\,080$$
г) $$(d-295)\cdot13=260$$
$$v\cdot1\,200=3\,600$$
$$25\cdot(540-s)=2\,500$$
$$6\,100:w=305$$
$$t:(6\,000-5\,996)=600$$
$$f:51=1\,000$$
$$(471+h):11=781$$Выполни действия. Если нужно, вырази величины в удобных единицах измерения.
$$68\ \text{см}^2+47\ \text{см}^2$$
$$16\ \text{дм}^2\cdot24$$
$$1\ \text{дм}^2\ 50\ \text{см}^2\cdot14$$
$$1\ \text{дм}^2\ 45\ \text{см}^2+2\ \text{дм}^2\ 74\ \text{см}^2$$
$$58\ \text{см}^2\cdot52$$
$$32\ \text{дм}^2\ 8\ \text{см}^2\cdot5$$
$$35\ \text{м}^2\ 59\ \text{дм}^2-7\ \text{м}^2\ 14\ \text{дм}^2$$
$$10\ \text{м}^2:25$$
$$13\ \text{м}^2\ 40\ \text{дм}^2:67$$
$$12\ \text{м}^2\ 13\ \text{дм}^2-84\ \text{дм}^2$$
$$36\ \text{дм}^2:72$$
$$52\ \text{дм}^2\ 6\ \text{см}^2:137$$Не выполняя точных вычислений, проверь последнюю цифру ответа. Какие вычисления выполнены с ошибкой?
$$8\,455+7\,276=15\,731$$
$$237\cdot4=942$$
$$8\,001:63=123$$
$$12\,654+13\,727=26\,383$$
$$659\cdot4=2\,636$$
$$3\,952:38=106$$
$$10\,366-4\,239=6\,127$$
$$735\cdot27=19\,840$$
$$18\,957:213=89$$
$$64\,273-25\,429=38\,843$$
$$496\cdot19=9\,424$$
$$67\,730:130=521$$
8.
а) $$68\,027 + 3\,784 = 71\,811$$
$$17\,329 + 28\,371 = 45\,700$$
$$342\,608 + 16\,492 = 359\,100$$
$$470\,852 + 609\,247 = 1\,080\,099$$
б) $$71\,029 — 6\,385 = 64\,644$$
$$34\,600 — 15\,480 = 19\,120$$
$$428\,095 — 74\,807 = 353\,288$$
$$120\,470 — 63\,542 = 56\,928$$
в) $$3\,789 + 6\,450 — 9\,230 = 10\,239 — 9\,230 = 1\,009$$
$$41\,315 — 7\,480 + 165 = 33\,835 + 165 = 34\,000$$
$$605\,402 — 84\,917 + 15 = 520\,485 + 15 = 520\,500$$
$$320\,317 + 94\,754 — 960 = 415\,071 — 960 = 414\,111$$
г) $$6\,024 \cdot 71 = 427\,704$$
$$2\,065 \cdot 45 = 92\,925$$
$$5\,068 \cdot 310 = 1\,571\,080$$
$$4\,207 \cdot 330 = 1\,388\,310$$
д) $$24\,875 \cdot 53 = 1\,318\,375$$
$$12\,290 \cdot 36 = 442\,440$$
$$30\,640 \cdot 74 = 2\,267\,360$$
$$20\,904 \cdot 85 = 1\,776\,840$$
е) $$1\,862 \cdot 260 = 484\,120$$
$$2\,016 \cdot 450 = 907\,200$$
$$4\,692 \cdot 181 = 849\,252$$
$$2\,790 \cdot 234 = 652\,860$$
ж) $$1\,687 \cdot 307 = 517\,909$$
$$2\,571 \cdot 504 = 1\,295\,784$$
$$3\,027 \cdot 206 = 623\,562$$
$$7\,142 \cdot 109 = 778\,478$$
9.
а) $$2109 + x = 10\,109$$
$$x = 10\,109 — 2109 = 8000$$
$$y — 954 = 39\,000$$
$$y = 39\,000 + 954 = 39\,954$$
$$85\,300 — z = 7300$$
$$z = 85\,300 — 7300 = 78\,000$$
$$k + 5962 = 225\,962$$
$$k = 225\,962 — 5962 = 220\,000$$
б) $$202 \cdot u = 8080$$
$$u = 8080 : 202 = 40$$
$$v \cdot 1200 = 3600$$
$$v = 3600 : 1200 = 3$$
$$6100 : w = 305$$
$$w = 6100 : 305 = 20$$
$$f : 51 = 1000$$
$$f = 1000 \cdot 51 = 51\,000$$
в) $$m — (647 — 47) = 3800$$
$$m — 600 = 3800$$
$$m = 3800 + 600 = 4400$$
$$60\,000 — (n + 12\,000) = 37\,000$$
$$n + 12\,000 = 60\,000 — 37\,000 = 23\,000$$
$$n = 23\,000 — 12\,000 = 11\,000$$
$$5682 — p + 18 = 1700$$
$$5682 — p = 1700 — 18 = 1682$$
$$p = 5682 — 1682 = 4000$$
$$r — 1908 — 92 = 4630$$
$$r — 1908 = 4630 + 92 = 4722$$
$$r = 4722 + 1908 = 6630$$
г) $$\left(d — 295\right)\cdot 13 = 260$$
$$d — 295 = 260 : 13 = 20$$
$$d = 20 + 295 = 315$$
$$25 \cdot (540 — s) = 2500$$
$$540 — s = 2500 : 25 = 100$$
$$s = 540 — 100 = 440$$
$$t : (6000 — 5996) = 600$$
$$t : 4 = 600$$
$$t = 600 \cdot 4 = 2400$$
$$\left(471 + h\right) : 11 = 781$$
$$471 + h = 781 \cdot 11 = 8591$$
$$h = 8591 — 471 = 8120$$
10.
$$68\ \text{см}^2 + 47\ \text{см}^2 = 115\ \text{см}^2 = 1\ \text{дм}^2\ 15\ \text{см}^2$$
$$1\ \text{дм}^2\ 45\ \text{см}^2 + 2\ \text{дм}^2\ 74\ \text{см}^2 = 145\ \text{см}^2 + 274\ \text{см}^2 = 419\ \text{см}^2 = 4\ \text{дм}^2\ 19\ \text{см}^2$$
$$35\ \text{м}^2\ 59\ \text{дм}^2 — 7\ \text{м}^2\ 14\ \text{дм}^2 = 3559\ \text{дм}^2 — 714\ \text{дм}^2 = 2845\ \text{дм}^2 = 28\ \text{м}^2\ 45\ \text{дм}^2$$
$$12\ \text{м}^2\ 13\ \text{дм}^2 — 84\ \text{дм}^2 = 1213\ \text{дм}^2 — 84\ \text{дм}^2 = 1129\ \text{дм}^2 = 11\ \text{м}^2\ 29\ \text{дм}^2$$
$$16\ \text{дм}^2 \cdot 24 = 384\ \text{дм}^2 = 3\ \text{м}^2\ 84\ \text{дм}^2$$
$$58\ \text{см}^2 \cdot 52 = 3016\ \text{см}^2 = 30\ \text{дм}^2\ 16\ \text{см}^2$$
$$10\ \text{м}^2 : 25 = 1000\ \text{дм}^2 : 25 = 40\ \text{дм}^2$$
$$36\ \text{дм}^2 : 72 = 3600\ \text{см}^2 : 72 = 50\ \text{см}^2$$
$$1\ \text{дм}^2\ 50\ \text{см}^2 \cdot 14 = 150\ \text{см}^2 \cdot 14 = 2100\ \text{см}^2 = 21\ \text{дм}^2$$
$$32\ \text{дм}^2\ 8\ \text{см}^2 \cdot 5 = 3208\ \text{см}^2 \cdot 5 = 16\,040\ \text{см}^2 = 1\ \text{м}^2\ 60\ \text{дм}^2\ 40\ \text{см}^2$$
$$13\ \text{м}^2\ 40\ \text{дм}^2 : 67 = 1340\ \text{дм}^2 : 67 = 20\ \text{дм}^2$$
$$52\ \text{дм}^2\ 6\ \text{см}^2 : 137 = 5206\ \text{см}^2 : 137 = 38\ \text{см}^2$$
11.
Проверяем последнюю цифру результата по последним цифрам чисел.
$$8455 + 7276 = 15\,731$$ — верно;
$$12\,654 + 13\,727 = 26\,383$$ — неверно;
$$10\,366 — 4239 = 6127$$ — верно;
$$64\,273 — 25\,429 = 38\,843$$ — неверно;
$$237 \cdot 4 = 948$$ — неверно;
$$659 \cdot 4 = 2636$$ — верно;
$$735 \cdot 27 = 19\,845$$ — неверно;
$$496 \cdot 19 = 9424$$ — верно;
$$8001 : 63 = 127$$ — неверно;
$$3952 : 38 = 104$$ — неверно;
$$18\,957 : 213 = 89$$ — верно;
$$67\,730 : 130 = 521$$ — верно.
Ответ
8) а) $$71\,811,\ 45\,700,\ 359\,100,\ 1\,080\,099$$; б) $$64\,644,\ 19\,120,\ 353\,288,\ 56\,928$$; в) $$1009,\ 34\,000,\ 520\,500,\ 414\,111$$; г) $$427\,704,\ 92\,925,\ 1\,571\,080,\ 1\,388\,310$$; д) $$1\,318\,375,\ 442\,440,\ 2\,267\,360,\ 1\,776\,840$$; е) $$484\,120,\ 907\,200,\ 849\,252,\ 652\,860$$; ж) $$517\,909,\ 1\,295\,784,\ 623\,562,\ 778\,478$$.
9) $$x=8000,\ y=39\,954,\ z=78\,000,\ k=220\,000,\ u=40,\ v=3,\ w=20,\ f=51\,000,\ m=4400,\ n=11\,000,\ p=4000,\ r=6630,\ d=315,\ s=440,\ t=2400,\ h=8120$$.
10) $$1\ \text{дм}^2\ 15\ \text{см}^2,\ 4\ \text{дм}^2\ 19\ \text{см}^2,\ 28\ \text{м}^2\ 45\ \text{дм}^2,\ 11\ \text{м}^2\ 29\ \text{дм}^2,\ 3\ \text{м}^2\ 84\ \text{дм}^2,\ 30\ \text{дм}^2\ 16\ \text{см}^2,\ 40\ \text{дм}^2,\ 50\ \text{см}^2,\ 21\ \text{дм}^2,\ 1\ \text{м}^2\ 60\ \text{дм}^2\ 40\ \text{см}^2,\ 20\ \text{дм}^2,\ 38\ \text{см}^2$$.
11) С ошибкой выполнены: $$12\,654 + 13\,727$$, $$64\,273 — 25\,429$$, $$237 \cdot 4$$, $$735 \cdot 27$$, $$8001 : 63$$, $$3952 : 38$$.
