Buoyant force is checked from density, gravity, and displaced volume. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Displaced fluid weight gives buoyant force
Density 2, gravity 10, and displaced volume 3 give buoyant force 60 newtons.
2×10×3=60
The upward force is a displaced-fluid ledger
The buoyant force is not a material property here; it is the 60 newton displaced-fluid weight.