Addition with Regrouping: 78 + 15

Addition with Regrouping Calculator

What is 78 + 15?

Answer

78 + 15 =

93

With regrouping: 1 carry — into the tens

78 + 15 in a column. Carries are the small circled digits above the columns.
		1carry
		7	8
	+	1	5
		9	3

Column by column: 78 + 15

Ones: 8 + 5 = 13 — write 3, carry 1.
Tens: 7 + 1 + 1 = 9 — write 9.

78 + 15 = 93

Second check: 93 − 78 = 15

Similar examples to practise

Related Calculations

93 − 15 = 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 15

Example	Sum
52 + 15	67
54 + 15	69
58 + 15	73
63 + 15	78
65 + 15	80
67 + 15	82
69 + 15	84
71 + 15	86
74 + 15	89
76 + 15	91
78 + 15	93
83 + 15	98
85 + 15	100
89 + 15	104
92 + 15	107
94 + 15	109
98 + 15	113
105 + 15	120
136 + 15	151
172 + 15	187

FAQ

What is 78 + 15?

78 + 15 = 93

How do you check that 78 + 15 = 93?

Subtract one addend from the sum: 93 − 15 = 78, and 93 − 78 = 15. Getting the other addend back means the sum is right.

How many carries are there in 78 + 15?

1 carry: 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 15 + 78 the same as 78 + 15?

Yes. Addition is commutative, so both give 93; the column looks the same with either number on top.

See Also