Lời giải Bài tập Toán lớp 5 Nhân hai số thập phân có đáp án

Câu 1

Hướng dẫn chấm do TopStudy biên soạn, mang tính gợi ý

$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{5{,}2}\\{3{,}7}\end{array}} \\\,\,\,\,364\\\underline {\,156\,\,\,\,\,} \\19{,}24\end{array}$	$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{0{,}46}\\{\,\,\,8{,}1}\end{array}} \\\,\,\,\,\,\,\,\,\,\,46\\\underline {\,\,\,\,368\,\,\,\,} \\\,\,3{,}726\end{array}$	$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{12{,}9}\\{0{,}53}\end{array}} \\\,\,\,\,\,\,\,387\\\underline {\,\,\,\,645\,\,\,} \\\,\,6{,}837\end{array}$	$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{0{,}087}\\{\,\,\,\,\,2{,}4}\end{array}} \\\,\,\,\,\,\,\,\,\,\,348\\\underline {\,\,\,\,\,\,\,174\,\,\,} \\\,\,0{,}2088\end{array}$
$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{0{,}315}\\{\,\,\,\,\,6{,}8}\end{array}} \\\,\,\,\,\,\,\,2520\\\underline {\,\,\,\,\,1890\,\,\,\,} \\\,\,\,2{,}142\end{array}$	$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{27{,}4}\\{0{,}29}\end{array}} \\\,\,\,\,2466\\\underline {\,\,\,\,548\,\,\,\,} \\\,\,7{,}946\end{array}$	$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{1{,}73}\\{\,\,4{,}5}\end{array}} \\\,\,\,\,\,\,865\\\underline {\,\,\,692\,\,} \\\,7{,}785\end{array}$	$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{0{,}0092}\\{\,\,\,\,\,\,\,\,5{,}6}\end{array}} \\\,\,\,\,\,\,\,\,\,\,\,\,\,552\\\underline {\,\,\,\,\,\,\,\,\,\,460\,\,\,\,} \\\,\,0{,}05152\end{array}$
$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{9{,}64}\\{\,\,\,\,1{,}2}\end{array}} \\\,\,\,\,\,1928\\\underline {\,\,\,\,964\,\,\,\,} \\11{,}568\end{array}$	$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{0{,}0578}\\{\,\,\,\,\,\,\,\,3{,}9}\end{array}} \\\,\,\,\,\,\,\,\,\,\,5202\\\underline {\,\,\,\,\,\,\,1734\,\,\,} \\\,\,0{,}22542\end{array}$	$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{\,\,\,\,\,\,3{,}2}\\{0{,}076}\end{array}} \\\,\,\,\,\,\,\,\,\,\,152\\\underline {\,\,\,\,\,\,228\,\,\,} \\\,\,0{,}2432\end{array}$	$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{0{,}412}\\{\,\,\,\,\,7{,}3}\end{array}} \\\,\,\,\,\,\,\,1236\\\underline {\,\,\,2884\,\,\,} \\\,3{,}0076\end{array}$
$\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{0{,}1286}\\{\,\,\,\,\,\,\,9{,}4}\end{array}} \\\,\,\,\,\,\,\,\,\,5144\\\underline {\,\,\,\,11574\,\,\,} \\\,\,1{,}20884\end{array}$	$\begin{array}{l}\underline {\,\,\,\, \times \begin{array}{cccccccccccccccccccc}{2{,}507}\\{\,\,0{,}84}\end{array}} \\\,\,\,\,\,\,10028\\\underline {\,\,20056\,\,\,} \\\,2{,}10588\end{array}$	$\begin{array}{l}\underline {\,\,\, \times \begin{array}{cccccccccccccccccccc}{6{,}28}\\{\,\,6{,}9}\end{array}} \\\,\,\,\,\,5652\\\underline {\,\,3768\,\,\,} \\43{,}332\end{array}$	$\begin{array}{l}\underline {\,\,\, \times \begin{array}{cccccccccccccccccccc}{322{,}12}\\{\,\,\,\,\,\,\,\,6{,}8}\end{array}} \\\,\,\,\,\,257696\\\underline {\,\,\,193272\,\,} \\2190{,}416\end{array}$

Câu 2

Hướng dẫn chấm do TopStudy biên soạn, mang tính gợi ý

0,735 × 7,8 = 5,733 $\begin{array}{l}\underline {\, \times \begin{array}{cccccccccccccccccccc}{0{,}735}\\{\,\,\,\,\,7{,}8}\end{array}} \\\,\,\,\,\,5880\\\underline {\,\,5145\,\,\,} \\5{,}733\end{array}$	9,82 × 7,3 = 71,686 $\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{9{,}82}\\{\,\,7{,}3}\end{array}} \\\,\,\,\,2946\\\underline {\,6874\,\,\,} \\71{,}686\end{array}$	71,35 × 6,5 = 463,775 $\begin{array}{l}\,\,\underline {\, \times \begin{array}{cccccccccccccccccccc}{71{,}35}\\{\,\,\,\,\,6{,}5}\end{array}} \\\,\,\,\,\,35675\\\underline {\,\,42810\,\,\,} \\463{,}775\end{array}$
71,7 × 88,2 = 6323,94 $\begin{array}{l}\,\,\,\,\,\,\underline { \times \begin{array}{cccccccccccccccccccc}{71{,}7}\\{88{,}2}\end{array}} \\\,\,\,\,\,\,\,\,1434\\\,\,\,\,\,5736\\\underline {\,\,5736\,\,\,\,\,\,} \\6323{,}94\end{array}$	1,8 × 32,3 = 58,14 $\begin{array}{l}\underline { \times \begin{array}{cccccccccccccccccccc}{\,\,\,\,1{,}8}\\{32{,}3}\end{array}} \\\,\,\,\,\,\,\,\,54\\\,\,\,\,\,36\\\underline {\,\,54\,\,\,\,\,\,} \\58{,}14\end{array}$	6,19 × 0,458 = 2,83502 $\begin{array}{l}\underline {\,\,\,\, \times \begin{array}{cccccccccccccccccccc}{\,\,\,\,6{,}19}\\{0{,}458}\end{array}} \\\,\,\,\,\,\,\,\,\,4952\\\,\,\,\,\,\,3095\\\underline {\,\,\,2476\,\,\,\,\,\,} \\\,2{,}83502\end{array}$
8,7 × 9,5 = 82,65 $\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{8{,}7}\\{9{,}5}\end{array}} \\\,\,\,\,435\\\underline {\,783\,\,\,\,} \\82{,}65\end{array}$	19,4 × 4,1 = 79,54 $\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{19{,}4}\\{\,\,\,4{,}1}\end{array}} \\\,\,\,\,\,\,\,\,194\\\underline {\,\,\,\,776\,\,\,\,} \\\,\,79{,}54\end{array}$	54,5 × 0,7 = 38,15 $\begin{array}{l}\underline {\,\, \times \begin{array}{cccccccccccccccccccc}{54{,}5}\\{\,\,0{,}7}\end{array}} \\\,\,\,3815\\\underline {\,\,\,000} \,\,\,\,\\\,\,38{,}15\end{array}$

Câu 3

Hướng dẫn chấm do TopStudy biên soạn, mang tính gợi ý

2,34 × 1,5 = 3,51	0,5 × 4,6 = 2,3
2,3 × 1,4 = 3,22	1,5 × 0,8 = 1,2
0,7 × 5,2 = 3,64	3,15 × 0,8 = 2,52
4,5 × 0,4 = 1,8	0,95 × 4,6 = 4,37
1,6 × 1,5 = 2,4	6,7 × 1,24 = 8,308
0,175 × 6,4 = 1,12	2,83 × 3,2 = 9,056
3,5 × 0,6 = 2,1	7,4 × 0,63 = 4,662
1,2 × 3,5 = 4,2	0,75 × 3,6 = 2,7
2,7 × 0,3 = 0,81	9,1 × 2,75 = 25,025
4,12 × 0,8 = 3,296	4,25 × 1,8 = 7,65
5,2 × 0,5 = 2,6	0,39 × 7,2 = 2,808
0,9 × 2,2 = 1,98	5,6 × 3,14 = 17,584
2,5 × 1,6 = 4	2,7 × 0,148 = 0,3996
1,7 × 0,4 = 0,68	8,3 × 0,95 = 7,885
1,25 × 2,4 = 3	1,06 × 4,8 = 5,088
6,3 × 0,2 = 1,26	0,624 × 5,7 = 3,5568

Câu 4

Hướng dẫn chấm do TopStudy biên soạn, mang tính gợi ý

2,3 × 1,5 = 3,45	1,25 × 0,8 = 1
0,48 × 2,5 = 1,2	0,48 × 2,5 = 1,2
1,8 × 0,7 = 1,26	3,14 × 0,5 = 1,57
0,9 × 5,5 = 4,95	2,6 × 1,3 = 3,38
4,2 × 0,3 = 1,26	1,75 × 0,4 = 0,7
4,35 × 0,7 = 3,045	0,64 × 1,5 = 0,96
1,4 × 2,5 = 3,5	5,3 × 0,4 = 2,12
3,15 × 1,2 = 3,78	2,8 × 0,75 = 2,1
6,28 × 0,5 = 3,14	1,05 × 0,8 = 0,84
2,7 × 0,9 = 2,43	4,6 × 0,25 = 1,15
0,18 × 5 = 0,9	3,2 × 1,25 = 4
5,1 × 0,6 = 3,06	0,72 × 1,5 = 1,08
1,6 × 3,5 = 5,6	2,4 × 0,35 = 0,84
2,75 × 1,6 = 4,4	7,5 × 0,08 = 0,6
4,8 × 0,7 = 3,36	1,12 × 2,5 = 2,8
3,6 × 0,25 = 0,9	1,44 × 2,5 = 3,6

Câu 5

Hướng dẫn chấm do TopStudy biên soạn, mang tính gợi ý

0,325 × 2,4 = 0,78	1,44 × 0,875 = 1,26
3,75 × 0,16 = 0,6	0,112 × 5,5 = 0,616
2,64 × 0,375 = 0,99	4,8 × 0,125 = 0,6
0,96 × 1,25 = 1,2	3,24 × 0,25 = 0,81
1,08 × 0,75 = 0,81	0,144 × 6,25 = 0,9
5,6 × 0,175 = 0,98	2,16 × 0,45 = 0,972

Câu 6

Hướng dẫn chấm do TopStudy biên soạn, mang tính gợi ý

12,5 × 0,8 = 10	2,25 × 4,4 = 9,9
0,75 × 16,8 = 12,6	33,2 × 0,15 = 4,98
8,4 × 1,25 = 10,5	0,96 × 12,5 = 12
150,8 × 0,04 = 6,032	2,64 × 3,75 = 9,9
0,125 × 80,5 = 10,0625	45,6 × 0,22 = 10,032
6,25 × 1,6 = 10	0,36 × 27,5 = 9,9
22,8 × 0,45 = 10,26	1,8 × 5,5 = 9,9
0,4 × 25,11 = 10,044	66,1 × 0,15 = 9,915
3,75 × 2,4 = 9	12,8 × 0,825 = 10,56
0,55 × 18,8 = 10,34	24,7 × 0,5 = 12,35

Câu 7

Hướng dẫn chấm do TopStudy biên soạn, mang tính gợi ý

2,7 × 3,4 = 9,18	24,6 × 1,7 = 41,82
15,3 × 2,8 = 42,84	32,5 × 1,3 = 42,25
11,2 × 3,8 = 42,56	25,4 × 1,65 = 41,91
1,9 × 5,2 = 9,88	1,8 × 4,4 = 7,92
13,7 × 3,1 = 42,47	23,5 × 1,8 = 42,3
16,4 × 2,6 = 42,64	5,1 × 1,2 = 6,12
4,3 × 1,7 = 7,31	26,5 × 1,6 = 42,4
17,5 × 2,4 = 42	20,5 × 2,06 = 42,23
18,3 × 2,3 = 42,09	1,4 × 6,5 = 9,1

Câu 8

Hướng dẫn chấm do TopStudy biên soạn, mang tính gợi ý

1,2 × 3,4 = 4,08	2,3 × 1,5 = 3,45
0,8 × 5,5 = 4,4	63,5 × 1,34 = 85,09
2,4 × 1,3 = 3,12	0,7 × 6,2 = 4,34
47,8 × 1,78 = 85,084	3,2 × 1,25 = 4
0,9 × 4,8 = 4,32	2,6 × 1,6 = 4,16
3,5 × 1,2 = 4,2	12,9 × 6,59 = 85,011
2,1 × 1,9 = 3,99	0,6 × 7,5 = 4,5

Câu 9

Hướng dẫn chấm do TopStudy biên soạn, mang tính gợi ý

1,3 × 2,4 = 3,12	21,6 × 1,875 = 40,5
2,1 × 1,5 = 3,15	1,2 × 2,8 = 3,36
0,7 × 5,2 = 3,64	1,6 × 2,1 = 3,36
1,4 × 2,5 = 3,5	15,3 × 2,68 = 41,004
0,35 × 4,8 = 1,68	1,5 × 2,2 = 3,3
56,2 × 1,52 = 85,424	1,8 × 1,8 = 3,24
1,7 × 1,9 = 3,23	0,5 × 7,2 = 3,6
9,8 × 1,3 = 12,74	1,1 × 3,2 = 3,52
17,6 × 4,83 = 85,008	1,9 × 1,7 = 3,23