Both 4.8 and 2.7 round up to give the estimate 5 + 3 = 8. Where is the exact sum compared with 8?

الشرح

The exact sum is 4.8 + 2.7 = 7.5, so it is lower than 8. Because both addends were rounded upward, their rounded sum must be above the true sum; claiming equality ignores the discarded tenths.