Set 5 in 1 Leonardo puzzles mix

4 puzzles + 1 mathematical puzzle hidden in one of the puzzles.

Goal:

Secret box: Open the box.

Secret padlock: Open the padlock.

Trapped nails: Separate the nails and connect them as before.

3D wooden cube: Take apart and put together.

Mathematical puzzle: Obtain the same sum in each column.

Difficulty:

Secret box: 4/6

Secret padlock: 3/6

Trapped nails: 4/6

3D wooden cube: 3/6

Mathematical puzzle: 3/6

Dimensions:

Secret box: 7.5 x 9.4 x 4.3 cm

Secret padlock: 6 x 4.5 x 1.5 cm

Trapped nails: 5 x 5 x 2 cm

3D wooden cube: 5 x 5 x 5 cm