Read posting Sarin participates in school anniversary event part 1 for school anniversary.
Lower primary school mathematics question LPQ27
The teacherincharge, 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