28奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)

1、因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)人教版 數(shù)學(xué) 五年級(jí) 下冊(cè)奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)情境導(dǎo)入情境導(dǎo)入探究新知探究新知課堂小結(jié)課堂小結(jié)課后作業(yè)課后作業(yè)因數(shù)與倍數(shù)因數(shù)與倍數(shù)課堂練習(xí)課堂練習(xí)2 2因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)是是2 2的倍數(shù)的倍數(shù)的數(shù)叫作的數(shù)叫作偶數(shù)偶數(shù)。不不是是2 2的倍的倍數(shù)的數(shù)數(shù)的數(shù)叫叫作作奇奇數(shù)數(shù)。個(gè)位上是個(gè)位上是0 0、2 2、4 4、6 6、8 8的數(shù)的數(shù), ,都是都是2 2的的倍數(shù)倍數(shù)。返回情境導(dǎo)情境導(dǎo)入入因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì) 奇數(shù)奇數(shù)與偶數(shù)的和是奇數(shù)還是偶數(shù)與偶數(shù)的和是奇數(shù)還是偶數(shù)? ?奇數(shù)與奇數(shù)與奇數(shù)的和是奇數(shù)還是偶數(shù)奇數(shù)的和是奇數(shù)還是

2、偶數(shù)? ?偶數(shù)與偶數(shù)的和呢偶數(shù)與偶數(shù)的和呢? ?2探究新知探究新知返回從題目中你知道從題目中你知道了什么？了什么？因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)奇數(shù)偶數(shù)奇數(shù)偶數(shù)= =奇數(shù)奇數(shù)？偶數(shù)？偶數(shù)？奇數(shù)奇數(shù)奇數(shù)奇數(shù)= =奇數(shù)？奇數(shù)？偶數(shù)？偶數(shù)？偶數(shù)偶數(shù)偶數(shù)偶數(shù)= =奇數(shù)？奇數(shù)？偶數(shù)？偶數(shù)？題目讓我們對(duì)奇題目讓我們對(duì)奇數(shù)、偶數(shù)的和做數(shù)、偶數(shù)的和做一些探索。一些探索。返回因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)可以隨意可以隨意找?guī)讉€(gè)找?guī)讉€(gè)奇數(shù)、偶數(shù)相加奇數(shù)、偶數(shù)相加。奇數(shù)奇數(shù)：5,7,9,115,7,9,11, ,偶數(shù)：偶數(shù)：8,12,20,248,12,20,24,5 58=138=137 78=158=155

3、 57=127=127 79=169=168 812=2012=20121224=3624=36返回因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)奇數(shù)奇數(shù)：5,7,9,115,7,9,11, ,偶數(shù)：偶數(shù)：8,12,20,248,12,20,24,5 58=138=137 78=158=155 57=127=127 79=169=168 812=2012=20121224=3624=36奇數(shù)奇數(shù)偶數(shù)偶數(shù)= =奇數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)= =偶偶數(shù)數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)= =偶偶數(shù)數(shù)返回因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)奇數(shù)奇數(shù)偶數(shù)偶數(shù)= =奇數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)= =偶偶數(shù)數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)= =偶偶數(shù)數(shù)返回奇數(shù)

4、：奇數(shù)：偶數(shù)：偶數(shù)：因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)這個(gè)結(jié)論正確嗎？這個(gè)結(jié)論正確嗎？可以再找一可以再找一些大數(shù)試試。些大數(shù)試試。319+534=853319+534=853533+319=852533+319=852534+320=854534+320=854奇數(shù)奇數(shù)偶數(shù)偶數(shù)= =奇數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)= =偶偶數(shù)數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)= =偶偶數(shù)數(shù)返回因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)奇數(shù)偶數(shù)奇數(shù)偶數(shù)= =奇數(shù)奇數(shù)？偶數(shù)？偶數(shù)？奇數(shù)奇數(shù)奇數(shù)奇數(shù)= =奇數(shù)奇數(shù)？偶數(shù)？偶數(shù)？偶數(shù)偶數(shù)偶數(shù)偶數(shù)= =奇數(shù)？奇數(shù)？偶數(shù)？偶數(shù)？如果是減法呢？如果是減法呢？返回因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)同樣找一些奇數(shù)同

5、樣找一些奇數(shù)和偶數(shù)相減。和偶數(shù)相減。11118=38=39 97=27=2202012=812=8奇數(shù)偶數(shù)奇數(shù)偶數(shù)= =奇數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)= =偶偶數(shù)數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)= =偶偶數(shù)數(shù)返回因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì) 奇數(shù)奇數(shù)與偶數(shù)與偶數(shù)的積是的積是奇數(shù)還是偶數(shù)奇數(shù)還是偶數(shù)? ?奇數(shù)與奇奇數(shù)與奇數(shù)數(shù)的積是的積是奇數(shù)還是偶數(shù)奇數(shù)還是偶數(shù)? ?偶數(shù)與偶數(shù)偶數(shù)與偶數(shù)的積呢的積呢? ?題目讓我們對(duì)奇題目讓我們對(duì)奇數(shù)、偶數(shù)的數(shù)、偶數(shù)的積積做做一些探索。一些探索?？梢噪S意可以隨意找?guī)讉€(gè)奇找?guī)讉€(gè)奇數(shù)、偶數(shù)數(shù)、偶數(shù)相乘相乘。課堂課堂練習(xí)練習(xí)返回因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)奇數(shù)奇數(shù)：5,7,9,11

6、5,7,9,11, ,偶數(shù)：偶數(shù)：8,12,20,248,12,20,24,5 58=408=407 78=568=565 57=357=357 79=639=638 812=9612=968 820=16020=160奇數(shù)奇數(shù)偶數(shù)偶數(shù)= =偶偶數(shù)數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)= =奇數(shù)奇數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)= =偶偶數(shù)數(shù)返回因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)不計(jì)算不計(jì)算, ,直接判斷結(jié)果是奇數(shù)還是偶數(shù)。直接判斷結(jié)果是奇數(shù)還是偶數(shù)。12+1612+16 16-1216-12 103-71103-71 13+7113+71 114+25114+25 19-1219-12 11111313 31314 4 141

7、48 8奇數(shù)奇數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)偶數(shù)偶數(shù)偶數(shù)偶數(shù)返回因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)遠(yuǎn)遠(yuǎn)到面包房去買面包遠(yuǎn)遠(yuǎn)到面包房去買面包, ,一個(gè)甜甜圈一個(gè)甜甜圈2 2元元, ,一個(gè)三明治一個(gè)三明治1010元元, ,一個(gè)巧克力面包一個(gè)巧克力面包3 3元。如果遠(yuǎn)遠(yuǎn)買了一些甜甜圈和元。如果遠(yuǎn)遠(yuǎn)買了一些甜甜圈和三明治三明治, ,他付給售貨員他付給售貨員5050元元, ,找回找回1111元元, ,找得對(duì)找得對(duì)嗎嗎? ?說明說明理由。理由。返回答：答：1111是奇數(shù)是奇數(shù), ,所以找得所以找得不對(duì)不對(duì)。因數(shù)與倍數(shù) 奇數(shù)和偶數(shù)的運(yùn)算性質(zhì)這節(jié)課你們都學(xué)會(huì)了哪些知識(shí)？這節(jié)課你們都學(xué)會(huì)了哪些知識(shí)？課堂小結(jié)課堂小結(jié)奇數(shù)奇數(shù)偶數(shù)偶數(shù)= =偶偶數(shù)數(shù)奇數(shù)奇數(shù)奇數(shù)奇數(shù)= =奇數(shù)奇數(shù)