Add Three-Digit Numbers With Carrying - Arithmetic Step by Step

Add 386 + 247 column by column, carrying in both the ones place (6+7=13) and the tens place (8+4+1=13) to get 633.

Example

add-386-247.math

   386
+  247
------

step: ones: 6 + 7 = 13, write 3, carry 1
step: tens: 8 + 4 + carry 1 = 13
step: hundreds: 3 + 2 + carry 1 = 6
step: 386 + 247 = 633

carry A carry propagates when a column sum is 10 or more: write the ones digit and carry 1 to the next column. This can happen in multiple columns in the same problem.

regrouping A carry is a form of regrouping: 10 ones become 1 ten, or 10 tens become 1 hundred. Each carry moves 1 group to the column on the left.