Grade 3 Math

Add 3-digit numbers

Add 3-digit numbers helps children practise adding three-digit numbers including ones, using place-value thinking and checking with estimates. Read the short guide and look through the examples before choosing online practice or a printable worksheet.

How to solve this

  • To add three-digit numbers, align ones under ones, tens under tens, hundreds under hundreds, and add column by column from right to left.
  • Carry any overflow from ones to tens, and from tens to hundreds.
  • Check by swapping the addends (addition is commutative) and re-adding; you should get the same sum.

Examples

347 + 251 = ?

598

428 + 367 = ?

795