Joseph Saw's answer to Aishah's Primary 5 Maths question.
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Draw out two sets of models - before and after. Selene has 4 times as much as Cathy, which means that Selene has 3 units more than Cathy.
When Selene has spent $12 and Cathy receives $6, they have the same amount. By cutting up that amount into two parts, we find that Cathy has $6 (received) plus her original amount. If you copy that into Selene's model, you will see that Selene will have one unit as well, plus ($6+$12). That is the amount she has more than Cathy, which is equal to 3 units.
Therefore 3 units = $18.
When Selene has spent $12 and Cathy receives $6, they have the same amount. By cutting up that amount into two parts, we find that Cathy has $6 (received) plus her original amount. If you copy that into Selene's model, you will see that Selene will have one unit as well, plus ($6+$12). That is the amount she has more than Cathy, which is equal to 3 units.
Therefore 3 units = $18.
Date Posted:
6 years ago
Thank you Mr.Saw.Much appreciated.
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