《2025年口算训练六年级数学上册人教版双色升级版》

$15:27=$$5:9$
$0.5:0.75=$$2:3$
$1.35:5=$$27:100$
$0.4:8=$$1:20$
$\frac {1}{5}:\frac {1}{20}=$$4:1$
$51:17=$$3:1$
$1.9:5.7=$$1:3$
$\frac {7}{9}:\frac {2}{3}=$$7:6$
$\frac {2}{15}:\frac {2}{3}=$$1:5$
$\frac {1}{16}:\frac {3}{8}=$$1:6$
$11.4:2=$$57:10$
$7.8:0.3=$$26:1$
$\frac {5}{8}:\frac {5}{7}=$$7:8$
$6:1.2=$$5:1$
$\frac {13}{24}:\frac {1}{3}=$$13:8$
$12:54=$$2:9$

答案： 解析：本题考查的是化简比的知识点。化简比就是找到两个数的最大公约数或者将小数、分数化为整数比，然后进行约分。
答案：
$15:27 = 5:9$
$0.5:0.75 = 2:3$
$1.35:5 = 27:100$
$0.4:8 = 1:20$
$\frac{1}{5}:\frac{1}{20} = 4:1$
$51:17 = 3:1$
$1.9:5.7 = 1:3$
$\frac{7}{9}:\frac{2}{3} = 7:6$
$\frac{2}{15}:\frac{2}{3} = 1:5$
$\frac{1}{16}:\frac{3}{8} = 1:6$
$11.4:2 = 57:10$
$7.8:0.3 = 26:1$
$\frac{5}{8}:\frac{5}{7} = 7:8$
$6:1.2 = 5:1$
$\frac{13}{24}:\frac{1}{3} = 13:8$
$12:54 = 2:9$

$\frac {9}{8}÷6= $
$\frac {6}{17}÷4= $
$\frac {3}{5}÷6= $
$\frac {5}{13}÷2= $
$\frac {1}{4}÷6= $
$\frac {5}{11}÷15= $
$\frac {2}{3}÷4= $
$\frac {3}{7}÷2= $
$\frac {1}{3}÷6= $
$\frac {4}{7}÷2= $
$\frac {9}{17}÷3= $
$\frac {8}{19}÷4= $
$\frac {6}{17}÷12= $

答案： 解析：
这些题目都是分数除以整数的计算题。分数除以整数的方法是将被除数的分子分母同时乘以整数的倒数，即$\frac{a}{b} ÷ c = \frac{a}{b} × \frac{1}{c} = \frac{a}{b × c}$。
答案：
$\frac {9}{8}÷6$
= $\frac{9}{8} × \frac{1}{6}$
= $\frac{9}{48}$
= $\frac{3}{16}$；
$\frac {6}{17}÷4$
= $\frac{6}{17} × \frac{1}{4}$
= $\frac{6}{68}$
= $\frac{3}{34}$；
$\frac {3}{5}÷6$
= $\frac{3}{5} × \frac{1}{6}$
= $\frac{3}{30}$
= $\frac{1}{10}$；
$\frac {5}{13}÷2$
= $\frac{5}{13} × \frac{1}{2}$
= $\frac{5}{26}$；
$\frac {1}{4}÷6$
= $\frac{1}{4} × \frac{1}{6}$
= $\frac{1}{24}$；
$\frac {5}{11}÷15$
= $\frac{5}{11} × \frac{1}{15}$
= $\frac{5}{165}$
= $\frac{1}{33}$；
$\frac {2}{3}÷4$
= $\frac{2}{3} × \frac{1}{4}$
= $\frac{2}{12}$
= $\frac{1}{6}$；
$\frac {3}{7}÷2$
= $\frac{3}{7} × \frac{1}{2}$
= $\frac{3}{14}$；
$\frac {1}{3}÷6$
= $\frac{1}{3} × \frac{1}{6}$
= $\frac{1}{18}$；
$\frac {4}{7}÷2$
= $\frac{4}{7} × \frac{1}{2}$
= $\frac{4}{14}$
= $\frac{2}{7}$；
$\frac {9}{17}÷3$
= $\frac{9}{17} × \frac{1}{3}$
= $\frac{9}{51}$
= $\frac{3}{17}$；
$\frac {8}{19}÷4$
= $\frac{8}{19} × \frac{1}{4}$
= $\frac{8}{76}$
= $\frac{2}{19}$；
$\frac {6}{17}÷12$
= $\frac{6}{17} × \frac{1}{12}$
= $\frac{6}{204}$
= $\frac{1}{34}$。

$20:(80)= \frac {1}{4}$
$3:(9)= \frac {1}{3}$
$10:(8)= \frac {5}{4}$
$40:(56)= \frac {5}{7}$
$(5):10= \frac {1}{2}$
$(12):40= \frac {3}{10}$
$(12):30= \frac {2}{5}$
$(21):70= \frac {3}{10}$
$(20):24= \frac {5}{6}$
$27:(45)= \frac {3}{5}$
$25:(40)= \frac {5}{8}$
$30:(40)= \frac {3}{4}$
$12:(72)= \frac {1}{6}$

答案： 解析：这些题目都是关于比例的问题，需要找到一个数，使得两个数的比等于给定的分数。可以通过设置等式，然后解这个等式来找到缺失的数。
答案：
$20:( 80 )= \frac {1}{4}$
$20 ÷ 80 = \frac{1}{4}$
$3:( 9 )= \frac {1}{3}$
$3 ÷ 9 = \frac{1}{3}$
$10:( 8 )= \frac {5}{4}$
$10 ÷ 8 = \frac{5}{4}$
$40:( 56 )= \frac {5}{7}$
$40 ÷ 56 = \frac{5}{7}$
$( 5 ):10= \frac {1}{2}$
$5 ÷ 10 = \frac{1}{2}$
$( 12 ):40= \frac {3}{10}$
$12 ÷ 40 = \frac{3}{10}$
$( 12 ):30= \frac {2}{5}$
$12 ÷ 30 = \frac{2}{5}$
$( 21 ):70= \frac {3}{10}$
$21 ÷ 70 = \frac{3}{10}$
$( 20 ):24= \frac {5}{6}$
$20 ÷ 24 = \frac{5}{6}$
$27:( 45 )= \frac {3}{5}$
$27 ÷ 45 = \frac{3}{5}$
$25:( 40 )= \frac {5}{8}$
$25 ÷ 40 = \frac{5}{8}$
$30:( 40 )= \frac {3}{4}$
$30 ÷ 40 = \frac{3}{4}$
$12:( 72 )= \frac {1}{6}$
$12 ÷ 72 = \frac{1}{6}$