4.包裝【對(duì)點(diǎn)訓(xùn)練】1.列豎式計(jì)算。(1)9.8×5.20.32×0.45.6×0.3=50.96=0.128=1.68(2)4.8×3.250.6×0.453.42×0.5=15.6=0.27=1.71(3)0.8×0.050.12×0.051.002×0.005=0.04=0.006=0.00501教材練一練P41T5媽媽想買3.8千克香蕉，25元夠嗎？【示范解答】5.90×3.8=22.42(元)22.42元＜25元答：25元夠。運(yùn)用類推法巧解題計(jì)算：【示范解答】【對(duì)點(diǎn)訓(xùn)練】2.計(jì)算。【基礎(chǔ)題】1.看誰算得又對(duì)又快。0.12×6= 30×0.4= 0.25×4=0.9×0.8= 2.1×0.7= 2.5×0.4=0.721210.721.4712.給下面各式的積補(bǔ)上小數(shù)點(diǎn)，并相應(yīng)添上或去掉“0”。0.0.3.選一選。(把正確答案的選項(xiàng)填在括號(hào)里)(1)根據(jù)2.6×180=468，積是4.68的算式是()。A.2.6×1.8B.26×1.8C.0.26×1.8(2)下面各題的積最大的是()。A.32×0.26B.3.2×0.26C.0.0032×260AA4.錯(cuò)題回收站。5.列豎式計(jì)算并驗(yàn)算下面各題。8.65×2.8 0.56×0.14=24.22=0.07843.14×0.08 3.8×0.25=0.2512=0.95【能力題】6.在里填上“＞”或“＜”。＞＜＜＜7.馬的奔跑速度是40.5千米/時(shí)。(1)鴕鳥的奔跑速度是多少千米/時(shí)？40.5×1.62=65.61(千米/時(shí))答：鴕鳥的奔跑速度是65.61千米/時(shí)。(2)獵豹的奔跑速度是多少千米/時(shí)？40.5×2.9=117.45(千米/時(shí))答：獵豹的奔跑速度是117.45千米/時(shí)。8.你知道軍軍學(xué)校花園的長(zhǎng)是多少嗎？13.8×1.5=20.7(m)答：軍軍學(xué)?；▓@的長(zhǎng)是20.7m。9.給一個(gè)長(zhǎng)2.4m，寬0.8m的長(zhǎng)方形宣傳欄刷油漆，每平方米要用油漆0.9kg。一共需要多少千克油漆？2.4×0.8=1.92(m2)1.92×0.9=1.728(kg)答：一共需要1.728kg油漆?！咎骄款}】10.將下面算式補(bǔ)充完整。38580300896內(nèi)容總結(jié)4.包裝。(1)9.8×5.20.32×0.45.6×0.3。(2)4.8×3.250.6×0.453.42×0.5。(3)0.8×0.050.12×0.051.002×0.005。5.90×3.8=22.42(元)22.42元＜25元答：25元夠。0.12×6= 30×0.4= 0.25×4=。(1)根據(jù)2.6×180=468，積是4.68的算式是()。A.2.6×1.8B.26×1.8C.0.26×1.8。(2)下面各題的積最大的是()。A.32×0.26B.3.2×0.26C.0.0032×260。8.65×2.8 0.56×0.14。3.14