On 0.15.90.7
NVIDIA Shield Tablet (touch) and Shield TV (controller)
Android 6.0.1
When using the enchanting table, it is deducting the same number of levels as lapis (1-3), and not the level of the enchantment shown on the right.
Linked issues
Comments 4
That is not consistent with what I've experienced with the Java version. Perhaps a mod was modifying that behavior.
To clarify what the previous comment says, Java edition's 1.8 update changed enchanting to work like it currently does (only using up as many levels as the number of lapis required) in the current Java edition and MCPE, and the older behavior from 1.7 and earlier was never used in MCPE as 1.8 had already come out when enchanting was added to MCPE in 0.12.0.
This works as intended. The green number at right is the required level for the player to use that enchantment, not the cost in levels. The cost in levels is always 1, 2 or 3 levels of experience depending on the corresponding position in the enchantment table.
See MCPE-11023 for more details.