Rounding to Tens

When rounding to tens we look at which ten is closer.
If the number ends in 1, 2, 3 or 4, we round down.
If the number ends in 5, 6, 7, 8 or 9, we round up.

Example: 24 ≈ 20 (20 is closer than 30)
Example: 38 ≈ 40 (40 is closer than 30)