1 00:00:00,560 --> 00:00:05,830 有份香蕉燕麥鬆餅的食譜中,需要3/4杯的 2 00:00:05,830 --> 00:00:07,820 老式燕麥 3 00:00:07,820 --> 00:00:10,740 你只要做食譜的1/2 4 00:00:10,740 --> 00:00:13,230 會用到多少鬆餅? 5 00:00:13,230 --> 00:00:16,550 如果整份食譜需要用到3/4杯 6 00:00:16,550 --> 00:00:18,630 你只做食譜的一半,你需要的 7 00:00:18,630 --> 00:00:20,520 是3/4的一半,對吧? 8 00:00:20,520 --> 00:00:23,100 你需要的是老式燕麥數量的一半 9 00:00:23,100 --> 00:00:24,330 在整份食譜中 10 00:00:24,330 --> 00:00:28,440 所以你要的是3/4的1/2 11 00:00:31,010 --> 00:00:35,860 所以你把1/2乘以3/4,就等於 12 00:00:35,860 --> 00:00:37,550 分子乘以分子 13 00:00:37,550 --> 00:00:40,590 1乘以3是3 14 00:00:40,590 --> 00:00:42,960 2乘以4是8 15 00:00:42,960 --> 00:00:43,820 這樣就完成了! 16 00:00:43,820 --> 00:00:51,885 你需要3/8杯老式燕麥 17 00:00:51,885 --> 00:00:54,220 讓我們用圖示法表示,讓它看起來 18 00:00:54,220 --> 00:00:55,040 較為合理些 19 00:00:55,040 --> 00:00:59,560 我把3/4畫成這樣,或本質上 20 00:00:59,560 --> 00:01:02,400 在正常狀況中你所需要多少的燕麥,或是 21 00:01:02,400 --> 00:01:04,060 你要做出所有食譜的量 22 00:01:04,060 --> 00:01:06,950 讓我畫畫 23 00:01:06,950 --> 00:01:11,270 這代表整個杯子,我們將它 24 00:01:11,270 --> 00:01:15,040 分成四等分--讓我將它分好一點 25 00:01:15,040 --> 00:01:23,690 因此分成四等分,3/4代表3個 26 00:01:23,690 --> 00:01:28,290 所以這是1,2,3 27 00:01:28,290 --> 00:01:30,740 代表這麼多的麥片 28 00:01:30,740 --> 00:01:33,240 線再你只要一半,對吧? 29 00:01:33,240 --> 00:01:35,110 因為你做食譜的一半 30 00:01:35,110 --> 00:01:39,320 所以我們可以將它分為兩半 31 00:01:39,320 --> 00:01:41,700 讓我換一個新顏色 32 00:01:41,700 --> 00:01:44,600 所以你要使用的就是和橘色一樣多的燕麥 33 00:01:44,600 --> 00:01:46,270 我們只做食譜的一半,所以你需要 34 00:01:46,270 --> 00:01:47,645 一半的燕麥 35 00:01:50,440 --> 00:01:54,930 所以你需要這麼多的燕麥。 36 00:01:54,930 --> 00:01:56,790 讓我們想想 37 00:01:56,790 --> 00:01:59,190 相對於整個杯子 38 00:01:59,190 --> 00:02:02,520 一種方式是我們將每個分成4份 39 00:02:02,520 --> 00:02:05,360 或是4小塊,將杯子的4個區塊 40 00:02:05,360 --> 00:02:07,630 分成8等分 41 00:02:07,630 --> 00:02:09,000 看看這樣做會發生什麼事 42 00:02:09,000 --> 00:02:13,260 所以我們將每個1/4小塊分成 43 00:02:13,260 --> 00:02:14,530 兩部份 44 00:02:14,530 --> 00:02:16,510 讓我們將它們分成兩半 45 00:02:16,510 --> 00:02:19,340 這是第一塊 46 00:02:19,340 --> 00:02:22,810 分成兩半 47 00:02:22,810 --> 00:02:24,250 這是兩小塊 48 00:02:24,250 --> 00:02:26,300 這是第2塊 49 00:02:26,300 --> 00:02:30,390 分成1小塊,2小塊 50 00:02:30,390 --> 00:02:32,980 這是第3塊,分成1,2小塊 51 00:02:32,980 --> 00:02:35,805 這是第4塊,或第4的區塊 52 00:02:35,805 --> 00:02:37,950 分成兩部份。 53 00:02:37,950 --> 00:02:45,490 現在,對整體來說,代表的分數是多少? 54 00:02:45,490 --> 00:02:47,840 現在,我們有8小塊,對吧? 55 00:02:47,840 --> 00:02:50,810 1,2,3,4,5,6,7,8因為 56 00:02:50,810 --> 00:02:53,380 我們將這4塊分成8小塊 57 00:02:53,380 --> 00:02:56,650 所以8是分母,我們要的是 58 00:02:56,650 --> 00:02:57,980 3/4的一半,對吧? 59 00:02:57,980 --> 00:03:00,430 記住,3/4是橘色部份, 60 00:03:00,430 --> 00:03:02,170 讓我把它弄清楚些,因為 61 00:03:02,170 --> 00:03:04,110 這樣的畫法會混淆 62 00:03:04,110 --> 00:03:06,280 這裡是3/4 63 00:03:06,280 --> 00:03:09,090 所以這是3/4 64 00:03:09,090 --> 00:03:19,620 紫色顏色部分是3/4的1/2 65 00:03:19,620 --> 00:03:22,020 但讓我們用8小塊來想想 66 00:03:22,020 --> 00:03:24,180 8塊中有幾塊是紫色的? 67 00:03:24,180 --> 00:03:26,910 這裡有1個,2個 68 00:03:26,910 --> 00:03:30,820 3個,所以是3/8 69 00:03:30,820 --> 00:03:33,460 希望這樣有讓你理解或讓你 70 00:03:33,460 --> 00:03:35,260 了解圖形的意義 71 00:03:35,260 --> 00:03:36,800 當你在計算3/4的1/2的時候