1. 圈一圈，算一算。
16 × 3 =
25 × 3 =
○○○○○○○○○○○○○○○○
○○○○○○○○○○○○○○○○
○○○○○○○○○○○○○○○○

× =
× =
+ =

16×3=48
25×3=75
$20×3=60$
$5×3=15$
$60+15=75$
答：16乘3的结果是48，25乘3的结果是75。

2. $18×3=$
$\begin{array}{|c|c|c|}\hline× & 10 & 8 \\\hline3 & & \\\hline\end{array}$
$□ + □ = □$
$17×5=$
$\begin{array}{|c|c|c|}\hline× & 10 & 7 \\\hline5 & & \\\hline\end{array}$
$□ + □ = □$
$16×8=$
$\begin{array}{|c|c|c|}\hline× & & \\\hline& & \\\hline\end{array}$
$□ + □ = □$

$18×3=54$
$\begin{array}{|c|c|c|}\hline× & 10 & 8 \\\hline3 & 30 & 24 \\\hline\end{array}$
$30 + 24 = 54$
$17×5=85$
$\begin{array}{|c|c|c|}\hline× & 10 & 7 \\\hline5 & 50 & 35 \\\hline\end{array}$
$50 + 35 = 85$
$16×8=128$
$\begin{array}{|c|c|c|}\hline× & 10 & 6 \\\hline8 & 80 & 48 \\\hline\end{array}$
$80 + 48 = 128$

3.
34
× 2 =
11
× 6 =
4
× 21 =
12
× 5 =

26
× 3 =
7
× 12 =
23
× 4 =
18
× 3 =

34×2=68
11×6=66
4×21=84
12×5=60
26×3=78
7×12=84
23×4=92
18×3=54

4.（1）每只猴子拎了15千克水果，一共有多少千克水果？
（2）每车装27千克西瓜，一共装多少千克西瓜？

4. (1) 4 × 15 = 60(千克) (2) 27 × 3 = 81(千克)