Tasty Teasers

Number conundrums

1)

2)

3)

4)

3 x 4 = 12
13 x 4 = 52
54 x 3 = 162
12 = 3 + 4 + 5
2 x 6 = 3 + 4 + 5
3 + 6 = 4.5 x 2
⁹⁄₁₂ + ⁵⁄₃₄ + ⁷⁄₆₈

 

5)

The first step is to eliminate 5 and 7. If 5 was in the grid, the multiplication(s) including the 5 would be divisible by 5. But the multiplication(s) without the 5 would not be divisible by 5, since no other number between 1 and 9 is divisible by 5. Likewise with 7.

6)