1、從圖中，你知道了哪些數(shù)學(xué)信息？,根據(jù)這些信息，你能提出什么問題？,“壯壯”出生時(shí)的胸圍是多少？,“壯壯”出生時(shí)的體長(zhǎng)比“健健”長(zhǎng)多少？,“壯壯”出生時(shí)的身高比“健健”高多少？,“壯壯”出生時(shí)的體重比“健健”高多少？,我出生時(shí)的胸圍比健健多0.03米。,我出生時(shí)我的胸圍是0.77米。,“壯壯”出生時(shí)的胸圍是多少？,幾個(gè)0.01,豎式,試一試,幾個(gè)0.1,+,=,0.77,77個(gè)0.01,0.03,+,=,3個(gè)0.01,80個(gè)0.01,0.8,“壯壯”出生時(shí)的胸圍是多少？,0,返回,0.8,7個(gè)0.01加上3個(gè)0.01等于10個(gè)0.01，等于0.1。,“壯壯”出生時(shí)的胸圍是多少？,0.77,0.0

2、3,+,=,返回,7個(gè)0.1加上1個(gè)0.1等于8個(gè)0.1，等于0.8。,十 分 位,答：“壯壯”出生時(shí)的胸圍是0.8米。,0.77,0.03,+,0,0.8,0,“壯壯”出生時(shí)的胸圍是多少？,0.77 + 0.03 =,（米）,0,8,返回,個(gè) 位,百 分 位,+ 0. 3 4,0.,1.,+ 0. 5 5,想一想，進(jìn)行小數(shù)加法計(jì)算時(shí)，應(yīng)注意什么？,試一試,7,0. 3 2,0. 6 6,8,0,0,計(jì)算。,“壯壯”出生時(shí)的體長(zhǎng)比健健長(zhǎng)多少？,0.04,答：“壯壯”出生時(shí)的體長(zhǎng)比健健長(zhǎng)0.04米。,0.76,0.72,-,0,4,0,0,0. 0 4,+ 0. 7 2,0. 7 6,驗(yàn)算：,-

3、 1. 5 4,0.,0.,- 0. 7 8,想一想，進(jìn)行小數(shù)減法計(jì)算時(shí)，應(yīng)注意什么？,試一試,6,0. 9 4,2. 3 6,1,8,2,計(jì)算。,1.3,你會(huì)計(jì)算 1.3-1.25 嗎？,1.3 - 1.25 =,0.05,1.25,-,0,5,0,0.77,0.8,0,0.76,0.04,1.3,0.05,0,想一想，怎樣計(jì)算小數(shù)加減法？,小數(shù)加減點(diǎn)對(duì)齊，,從右往左來算起。,滿十進(jìn)一要牢記，,退一當(dāng)十別大意。,點(diǎn),這節(jié)課你有哪 些收獲？,1.火眼金睛辨對(duì)錯(cuò)。,1,4,7,6,1,7.06,6.5,6.41,6.5,0.56,5.9,- 3.58,2.48,2.32,0,2.計(jì)算。,+ 2. 2 1,1.,1 .,+ 0. 4 2,0,0. 7 8,8. 8 3,2,0,4,- 8. 5 3,2.,1.,- 0. 9 6,0,3. 1 6,1 0. 0 3,2,5,0,1,3.,一個(gè)身高170.2厘米的航天員飛上太空后，經(jīng)過一段時(shí)間，身高增加了5.5厘米。此時(shí)他的身高是多少厘米？,170.2 + 5.5 =,175.7（厘米）,答：此時(shí)他的身高是175.7厘米。,花了0.8元。,4.羊村長(zhǎng)病了，喜羊羊帶著10元錢去給村長(zhǎng)買藥。,應(yīng)該找回多少元？,10.0,- 0.8,9.2,