The blog postings are about the Singapore Math. The readers can learn from the postings on Solving Singapore Primary School Mathematics. The blog presents the Math Concept, the Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids will learn the skills of dealing with the Math Problem Solving, the Math Modeling and the Problem Sum from Lower Primary School to Upper Primary School level after reading the blog postings. This posting is an upper primary school math question on Percentage and Problem Sum.
You should read the posting on Sarin learns Average Number, Percentage and Charting in school (Math Concept) to understand Percentage.
Challenge yourself with the question before look out for the given solution‼!
Upper primary school mathematics question UPQ458
Hairu bought 220 stickers. 40% of them were blue stickers and the rest were green stickers. He gave Sarin some blue stickers and the percentage of blue stickers became 20%.
a) How many stickers did Hairu have left?
b) How many blue stickers did he give to Sarin?
Hairu bought 220 stickers
100% ==> 220
10% ==> 22
40% ==> 22 × 4 = 88 ==> the number of blue stickers
60% ==> 22 × 6 = 132 ==> the number of green stickers
Some blue stickers given to Sarin and became only 20% left
80% ==> 132 ==> the number of green stickers
10% ==> 16.5
100% ==>165 ==> the total number of stickers left
20% ==> 16.5 × 2 = 33
The number of blue stickers given to Sarin = 88 – 33 = 55