Addition with Regrouping: 78 + 39

Addition with Regrouping Calculator

What is 78 + 39?

Answer

78 + 39 =

117

The sum is longer than the addends: 2 carries — into the tens and the hundreds; the last one makes a new digit

78 + 39 in a column. Carries are the small circled digits above the columns.
		1carry	1carry
			7	8
	+		3	9
		1	1	7

Column by column: 78 + 39

Ones: 8 + 9 = 17 — write 7, carry 1.
Tens: 7 + 3 + 1 = 11 — write 1, carry 1.
Hundreds: the carried 1 — write 1.

78 + 39 = 117

Second check: 117 − 78 = 39

Similar examples to practise

Related Calculations

117 − 39 = 78 - Subtraction with Regrouping

See Also

Subtraction with Regrouping Calculator - Column subtraction step by step, with borrowing across zeros
Long Multiplication Calculator - Column multiplication with partial products, step by step
Long Division Calculator - Step-by-step long division with detailed explanation
Adding Fractions Calculator - Add fractions, mixed numbers and whole numbers step by step

Recalculate with different values ↑

Column additions with 39

Example	Sum
52 + 39	91
54 + 39	93
58 + 39	97
63 + 39	102
65 + 39	104
67 + 39	106
69 + 39	108
71 + 39	110
74 + 39	113
76 + 39	115
78 + 39	117
83 + 39	122
85 + 39	124
89 + 39	128
92 + 39	131
94 + 39	133
98 + 39	137
105 + 39	144
136 + 39	175
172 + 39	211

FAQ

What is 78 + 39?

78 + 39 = 117

How do you check that 78 + 39 = 117?

Subtract one addend from the sum: 117 − 39 = 78, and 117 − 78 = 39. Getting the other addend back means the sum is right.

How many carries are there in 78 + 39?

2 carries: every time a column added up to 10 or more, its ones digit was written and 1 was carried to the next column on the left.

Is 39 + 78 the same as 78 + 39?

Yes. Addition is commutative, so both give 117; the column looks the same with either number on top.

See Also