A pallet balance with two equal long arms can also be leveled, but it has no weight. The scale on the walking scale is 0 ~ 5g, and 50g should be weighed from a pile of sand.

1. Move the code to 5g, and put 5g sand on the left plate.

2. Move the sand to the right plate and put 10g sand on the left plate.

3. Move the sand to the plate on the right and put 20g of sand on the plate on the left.

4. Remove 20g sand from the left plate, move the swimming code to 0, and put 15g sand on the left plate to keep balance.

Finally, all the sand adds up to 50g. 20+ 15+ 15=50。