1. 如图,将数轴上的各点与下列实数对应起来,并把各数按从小到大的顺序排列,用“<”连接。
0.3,-$\sqrt{3}$,$\sqrt{2}$,3.14,-$\pi$,0,$\frac{7}{2}$。

答案:1.A:$-\pi$ B:$-\sqrt{3}$ C:$0$ D:$0.3$ E:$\sqrt{2}$ F:$3.14$ G:$\frac{7}{2}$
$-\pi<-\sqrt{3}<0<0.3<\sqrt{2}<3.14<\frac{7}{2}$
2. 有下列四个数:3,-$\sqrt{3}$,2,$\sqrt{10}$。其中,最大的是(
D
)
A.3
B.2
C.-$\sqrt{3}$
D.$\sqrt{10}$
答案:2.D
解析:
$\sqrt{9}=3$,$\sqrt{10}>\sqrt{9}$,即$\sqrt{10}>3$,$3>2>-\sqrt{3}$,最大的是$\sqrt{10}$。D
3. 比较大小:3
$\sqrt{7}$;$\frac{\sqrt{5}-1}{3}$_________$\frac{1}{3}$(填“>”或“<”)。
答案:3.$>$ $>$
4. 比较大小:
(1)$\sqrt{75}$与8;
(2)-$\sqrt{11}$与-3;
(3)$\sqrt{2}$与1.42;
(4)$\sqrt{12}-1$与3。
答案:4.(1)$\because(\sqrt{75})^2 = 75,8^2 = 64,75>64,\therefore\sqrt{75}>8$
(2)$\because(-\sqrt{11})^2 = 11,(-3)^2 = 9,11>9,\therefore-\sqrt{11}<-3$
(3)$\because(\sqrt{2})^2 = 2,1.42^2 = 2.0164,2<2.0164,\therefore\sqrt{2}<1.42$
(4)$\because(\sqrt{12})^2 = 12,4^2 = 16,12<16,\therefore\sqrt{12}<4.\therefore\sqrt{12}-1<3$
5. 比较大小:
(1)$1-\sqrt{2}$与$1-\sqrt{3}$;
(2)$\frac{\sqrt{3}-1}{5}$与$\frac{1}{5}$;
(3)$\frac{\sqrt{7}-2}{2}$与$\sqrt{7}-3$;
(4)$\frac{\sqrt{24}}{2}-1$与1.5。
答案:5.(1)$\because1-\sqrt{2}-(1-\sqrt{3})=\sqrt{3}-\sqrt{2}>0,\therefore1-\sqrt{2}>1-\sqrt{3}$
(2)$\frac{\sqrt{3}-1}{5}-\frac{1}{5}=\frac{\sqrt{3}-2}{5}\because\sqrt{3}<2,\therefore\frac{\sqrt{3}-2}{5}<0.\therefore\frac{\sqrt{3}-1}{5}<\frac{1}{5}$
(3)$\frac{\sqrt{7}-2}{2}-(\sqrt{7}-3)=2-\frac{\sqrt{7}}{2}=\frac{4-\sqrt{7}}{2}\because4>\sqrt{7}$,
$\therefore\frac{4-\sqrt{7}}{2}>0.\therefore\frac{\sqrt{7}-2}{2}>\sqrt{7}-3$(4)$\frac{\sqrt{24}}{2}-1-1.5=\frac{\sqrt{24}-5}{2}\because\sqrt{24}<5,\therefore\frac{\sqrt{24}-5}{2}<0.\therefore\frac{\sqrt{24}}{2}-1<1.5$
6. 比较实数2,$\sqrt{5}$,$\sqrt[3]{7}$的大小,正确的是(
A
)
A.$\sqrt[3]{7}<2<\sqrt{5}$
B.$2<\sqrt[3]{7}<\sqrt{5}$
C.$\sqrt{5}<\sqrt[3]{7}<2$
D.$2<\sqrt{5}<\sqrt[3]{7}$
答案:6.A 解析:$\because2=\sqrt{4}<\sqrt{5},\therefore2<\sqrt{5}.\because\sqrt[3]{7}<\sqrt[3]{8}=2,\therefore\sqrt[3]{7}<2.\therefore\sqrt[3]{7}<2<\sqrt{5}$.