Sarin participates in school anniversary event part 5(math question)

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Read posting Sarin participates in school anniversary event part 1 for school anniversary.

Lower primary school mathematics question LPQ27

The teacher-in-charge, Miss Lim bought some cupcakes for Sarin and his team. If she gives each member 6 cupcakes, she would have 12 cupcakes left. If she gives each member 8 cupcakes, she would need another 2 cupcakes. What was the smallest possible number of members in Sarin’s team (include Sarin as member)?

Solution:

                 Solve by Gap method,

                 She gives 8 – 6 = 2 extra in the two situations.

                 The different between the cupcakes that left over and short for = 12 + 2 = 14

                 Number of possible members  = 14 ÷ 2 = 7

                 Check: Total cupcakes = 7 × 6 + 12 = 54 = 7 × 8 – 2

Alternative solution 1:

            Draw a model as shown below,

 

 

 

 

            There are N blocks of 2. Derive from 8 – 6 = 2

            2N = 14

            N = number of members = 7

Alternative solution 2:

            Using Guess and Check method:      

Guess

 

Total cupcakes

 

Total cupcakes

Check

Number of members

6 cupcakes each member

Plus 12 cupcakes

8 cupcakes each member

Minor 2 cupcakes

Same number of cupcakes?

1

6

18

8

6

×

5

30

42

40

38

×

6

36

48

48

46

×

7

42

54

56

54

            Number of members = 7

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