Adding Hexadecimal Numbers: 2ABC+98F22ABC + 98F2

Adding Hexadecimal Numbers: 2ABC+98F22ABC + 98F2

Verified Sources
Nov 4, 2026

To add hexadecimal numbers, you apply the same “grade-school” idea as decimal addition, but with base 1616 instead of base 1010: add digits right-to-left, track carries, and treat digits 00–99 and AA–FF as values 00–1515. keyword
For our problem we compute 2ABC16+98F2162ABC_{16} + 98F2_{16}. We will show: (1) digit-by-digit base-1616 addition with carries, (2) a validation via conversion to decimal and back, and (3) generalizable patterns for future problems.

Key terms: hexadecimal numeral digit value carry base-16

Hexadecimal Addition (Carry) Tutorial

Let’s align the numbers by place value (units on the right).
2ABC162ABC_{16} has 4 hex digits; 98F21698F2_{16} has 4 hex digits, so we can line up directly:

Place (base 1616)2ABC162ABC_{16}98F21698F2_{16}
16316^32299
16216^2AA88
16116^1BBFF
16016^0CC22

We’ll add digit-by-digit from the rightmost column, using carry whenever a column sum reaches 1616 or more.

Digit-by-Digit Hex Addition with Carries

  1. 1
    Step 1

    Add C+2C + 2 (in hex digit values). Since C=12C=12, 12+2=1412+2=14, which is less than 1616, so the result digit is EE and carry is 00.

  2. 2
    Step 2

    Add B+F+carryB + F + carry. Here B=11B=11, F=15F=15, carry 00: 11+15=2611+15=26. In base 1616, 26=1⋅16+1026 = 1\cdot16 + 10, so remainder is AA and carry is 11.

  3. 3
    Step 3

    Add A+8+carryA + 8 + carry. Here A=10A=10, 8=88=8, carry 11: 10+8+1=1910+8+1=19. In base 1616, 19=1⋅16+319 = 1\cdot16 + 3, so remainder is 33 and carry is 11.

  4. 4
    Step 4

    Add 2+9+carry2 + 9 + carry. Here 2=22=2, 9=99=9, carry 11: 2+9+1=122+9+1=12. Since 12<1612<16, remainder digit is CC and carry becomes 00.

  5. 5
    Step 5

    Combine the column remainders from left to right: C 3 A EC\,3\,A\,E. Therefore, 2ABC16+98F216=C3AE162ABC_{16} + 98F2_{16} = C3AE_{16}.

Fast carry rule in base $16$

When a column sum is 2˘26516\u226516, write it as sum=16⋅carry+remainder\text{sum} = 16\cdot\text{carry} + \text{remainder}. The remainder directly becomes the hex digit (0–F).

Common mistake: forgetting that A–F represent 10–15

Always convert hex digits to their numeric values before adding: A=10A=10, B=11B=11, C=12C=12, D=13D=13, E=14E=14, F=15F=15. Otherwise carries will be wrong.

We now verify the result by converting to decimal and back.

1) Convert 2ABC162ABC_{16} to decimal

Using place values:

  • 2cdot163=2cdot4096=81922\\cdot 16^3 = 2\\cdot 4096 = 8192
  • Acdot162=10cdot256=2560A\\cdot 16^2 = 10\\cdot 256 = 2560
  • Bcdot161=11cdot16=176B\\cdot 16^1 = 11\\cdot 16 = 176
  • Ccdot160=12cdot1=12C\\cdot 16^0 = 12\\cdot 1 = 12

So: 2ABC16=8192+2560+176+12=109402ABC_{16} = 8192 + 2560 + 176 + 12 = 10940

2) Convert 98F21698F2_{16} to decimal

  • 9cdot163=9cdot4096=368649\\cdot16^3 = 9\\cdot4096 = 36864
  • 8cdot162=8cdot256=20488\\cdot16^2 = 8\\cdot256 = 2048
  • Fcdot161=15cdot16=240F\\cdot16^1 = 15\\cdot16 = 240
  • 2cdot160=2cdot1=22\\cdot16^0 = 2\\cdot1 = 2

So: 98F216=36864+2048+240+2=3915498F2_{16} = 36864 + 2048 + 240 + 2 = 39154

3) Add in decimal, then convert back

Sum: 10940+39154=5009410940 + 39154 = 50094

Now check C3AE16C3AE_{16}:

  • Ccdot163=12cdot4096=49152C\\cdot16^3 = 12\\cdot4096 = 49152
  • 3cdot162=3cdot256=7683\\cdot16^2 = 3\\cdot256 = 768
  • Acdot161=10cdot16=160A\\cdot16^1 = 10\\cdot16 = 160
  • Ecdot160=14cdot1=14E\\cdot16^0 = 14\\cdot1 = 14

So: C3AE16=49152+768+160+14=50094C3AE_{16} = 49152 + 768 + 160 + 14 = 50094

The decimals match, confirming: 2ABC16+98F216=C3AE16.2ABC_{16} + 98F2_{16} = C3AE_{16}.

Column Sums and Remainders (Base 16)

Each hex column is summed (including carry), then split into carry + remainder.

How to Solve Any Hex Addition Problem

Align digits

1

Place numbers so the rightmost digits line up by 16016^0 place."

Add right-to-left

2

Compute each column sum using digit values (AA–FF = 10–15)."

Compute carry and remainder

3

For sum ≥16\ge 16, carry is ⌊sum/16⌋\lfloor\text{sum}/16\rfloor and remainder is sum mod 16\text{sum}\bmod 16."

Convert remainder back to hex digit

4

Map remainder 0–15 to hex digit 0–F, then write the final result."

Common Edge Cases

Knowledge Check

Question 1 of 4
Q1Single choice

What is the value of hex digit BB in base 10?