Ratio and ProportionRatioA ratio compares the sizes of parts or quantities to each other.What is the ratio of red counters to blue counters?red : blue= 9 : 3= 3 : 1For ever three red counters there is one blue counter.What is the ratio of red counters to ello! counters to blue counters? Ratiored : ello! : blue= 1" : # : $=3: 1 : "For ever three red counters there is one ello! counter and t!o blue counters.Simplifying ratios%atios can be simpli&ed li'e fractions b dividin( each part b the hi(hest common factor."1 : 3)= 3 : ) 7 7For a three*part ratio all three parts must be divided b the same number.+ : 1" : 9= " : # : 3 3 3Dividing in a given ratioA ratio is made up of parts.We can !rite the ratio " : 3 as:" parts : 3 parts,he total number of parts is: " parts - 3 parts = ) parts.ivide /#0 in the ratio " : 3./#0 1 ) = /$We need to divide /#0 b the total number of parts.Proportion,here are man !as to e2press a proportion.We can e2press this proportion as:1" out of 1+ 3 in ever #3#0.3) or 3)4Proportion compares the size of a part to the size of a !hole.What proportion of these counters are red? Direct proportion problems3 pac'ets of crisps !ei(h 90 (.5o! much do + pac'ets !ei(h?3 pac'ets !ei(h 90 (. 2+ pac'ets !ei(h 21$0 (.6f !e double the number of pac'ets then !e double the !ei(ht.,he number of pac'ets and the !ei(hts are in direct proportion.7o! tr these:.ivide:Ans!ers:1. +:# ". 1+:# 3. 10:# #. 1$:+ ). 1):3+. 1+:1" 3. 10:+ $. )0:"0 9. 3):1010. )0:#011. 3):1) 1". 33:##13. +:1) 1#. 1+:"# 1). 3+:31+. $:$:# 13. +:#:" 1$. "):"0:)19. 1):10:)"0. 1):9:3 "1. #":"1:3 "". )+:"#:1+ "3. +0:3+:"#"#. 3):"$:"1 "). +0:"#:"# "+. /$08 /+0"3. +:9:1""$. +:$:10 "9. +0:1)0:"10 30. ".):10:1".)