《2025年同步练习西南大学出版社四年级数学上册西师大版四川专版》

1. 口算。
$21×40 = $840 $600×8 = $4800 $30×50 = $1500
$700×90 = $63000 $3×900 = $2700 $50×120 = $6000
$43×20 = $860 $320×4 = $1280 $80×40 = $3200

答案： 21×40 = 840
600×8 = 4800
30×50 = 1500
700×90 = 63000
3×900 = 2700
50×120 = 6000
43×20 = 860
320×4 = 1280
80×40 = 3200

2. 填空。
(1) 一个因数是 $350$,另一个因数是 $40$,积是(14000)。
(2) 最小的三位数乘最大的两位数,积是(9900)。
(3) 三位数乘两位数,积最小是(四)位数,最大是(五)位数。

答案：
(1) $14000$
(2) $9900$
(3) 四，五

3. 列竖式计算。
$430×60 = $$\begin{array}{r}430\\×\,\,\,\, 60\\\hline25800\\\end{array}$ $320×8 = $$\begin{array}{r}320\\×\,\,\,\,\,\,8\\\hline2560\\\end{array}$ $236×20 = $$\begin{array}{r}236\\×\,\,\,\, 20\\\hline4720\\\end{array}$
$315×11 = $$\begin{array}{r}315\\×\,\,\,\, 11\\\hline315\\315\!\!\!\!\!\\\hline3465\\\end{array}$ $19×530 = $$\begin{array}{r}530\\×\,\,\,\,19\\\hline4770\\530\!\!\!\\\hline10070\\\end{array}$ $40×710 = $$\begin{array}{r}710\\×\,\,\,\,40\\\hline28400\\\end{array}$
$42×703 = $$\begin{array}{r}703\\×\,\,\,\,42\\\hline1406\\28120\!\!\!\\\hline29526\\\end{array}$ $608×35 = $$\begin{array}{r}608\\×\,\,\,\,35\\\hline3040\\18240\!\!\!\\\hline21280\\\end{array}$ $65×120 = $$\begin{array}{r}120\\×\,\,\,\,65\\\hline600\\7200\!\!\!\\\hline7800\\\end{array}$

答案： 1. $430×60 = 25800$
$\begin{array}{r}430\\×\,\,\,\, 60\\\hline25800\\\end{array}$
2. $320×8 = 2560$
$\begin{array}{r}320\\×\,\,\,\,\,\,8\\\hline2560\\\end{array}$
3. $236×20 = 4720$
$\begin{array}{r}236\\×\,\,\,\, 20\\\hline4720\\\end{array}$
4. $315×11 = 3465$
$\begin{array}{r}315\\×\,\,\,\, 11\\\hline315\\315\!\!\!\!\!\\\hline3465\\\end{array}$
5. $19×530 = 10070$
$\begin{array}{r}530\\×\,\,\,\,19\\\hline4770\\530\!\!\!\\\hline10070\\\end{array}$
6. $40×710 = 28400$
$\begin{array}{r}710\\×\,\,\,\,40\\\hline28400\\\end{array}$
7. $42×703 = 29526$
$\begin{array}{r}703\\×\,\,\,\,42\\\hline1406\\28120\!\!\!\\\hline29526\\\end{array}$
8. $608×35 = 21280$
$\begin{array}{r}608\\×\,\,\,\,35\\\hline3040\\18240\!\!\!\\\hline21280\\\end{array}$
9. $65×120 = 7800$
$\begin{array}{r}120\\×\,\,\,\,65\\\hline600\\7200\!\!\!\\\hline7800\\\end{array}$