Adding Within 100: Grade 2 Math Worksheet Answer Key – PDF Download

Grade 2 Add Worksheet Answer Key: problems 1–5

Problem 1: Add tens

1. \(30+40=70\)
2. \(20+60=80\)
3. \(50+40=90\)
4. \(70+20=90\)

Problem 2: Blocks without regrouping

Tens: \(3+4=7\). Ones: \(2+5=7\).

\(32+45=77\)

Problem 3: Add tens to a number

1. \(47+30=77\)
2. \(25+50=75\)
3. \(62+20=82\)
4. \(18+70=88\)

Problem 4: Add ones, no regrouping

1. \(42+6=48\)
2. \(53+4=57\)
3. \(75+3=78\)
4. \(81+8=89\)

Problem 5: Add ones with regrouping

1. \(38+7=45\)
2. \(56+8=64\)
3. \(49+5=54\)
4. \(67+6=73\)

Grade 2 Add Worksheet Answer Key: problems 6–10

Problem 6: Blocks with regrouping

Ones: \(7+6=13\), which is 1 ten and 3 ones. Tens: \(2+1+1=4\).

\(27+16=43\)

Problem 7: Add two-digit numbers

1. \(34+25=59\)
2. \(42+36=78\)
3. \(51+47=98\)
4. \(63+24=87\)

Problem 8: Add with regrouping

1. Ones: \(6+7=13\), regroup. Tens: \(3+2+1=6\). \(36+27=63\)
2. Ones: \(8+5=13\), regroup. Tens: \(4+3+1=8\). \(48+35=83\)
3. Ones: \(9+4=13\), regroup. Tens: \(2+4+1=7\). \(29+44=73\)
4. Ones: \(5+9=14\), regroup. Tens: \(1+6+1=8\). \(15+69=84\)

Problem 9: Open number line

\(53+20=73\), then \(73+9=82\).

\(53+29=82\)

Problem 10: Break apart tens and ones

1. \(40+30=70\), \(6+7=13\), \(70+13=83\). \(46+37=83\)
2. \(50+20=70\), \(8+6=14\), \(70+14=84\). \(58+26=84\)
3. \(20+40=60\), \(9+3=12\), \(60+12=72\). \(29+43=72\)

Grade 2 Add Worksheet Answer Key: problems 11–15

Problem 11: Missing addend

1. \(26\): \(24+26=50\)
2. \(45\): \(36+45=81\)
3. \(32\): \(32+28=60\)
4. \(78\): \(15+78=93\)

Problem 12: Compare sums

1. \(72\) and \(70\): \(72 > 70\)
2. \(64\) and \(70\): \(64 < 70\)
3. \(60\) and \(60\): \(60 = 60\)
4. \(71\) and \(73\): \(71 < 73\)

Problem 13: Add three numbers

1. \(20+30+40=90\)
2. \(14+25+11=50\)
3. \(32+15+21=68\)
4. \(41+23+34=98\)

Problem 14: Three numbers with regrouping

1. \(28+15=43\), \(43+30=73\). \(28+15+30=73\)
2. \(19+27=46\), \(46+31=77\). \(19+27+31=77\)
3. \(24+38=62\), \(62+16=78\). \(24+38+16=78\)
4. \(35+26=61\), \(61+19=80\). \(35+26+19=80\)

Problem 15: Four numbers

\(12+23=35\) and \(31+14=45\). Then \(35+45=80\).

\(12+23+31+14=80\)

Grade 2 Add Worksheet Answer Key: problems 16–20

Problem 16: Four numbers with regrouping

1. \(27+16=43\) and \(34+19=53\). \(43+53=96\). \(27+16+34+19=96\)
2. \(18+22=40\) and \(35+25=60\). \(40+60=100\). \(18+22+35+25=100\)

Problem 17: Check by subtracting

\(64+19=83\). Check: \(83-19=64\) (take away 10 to get 73, then 9 more to get 64).

The sum is 83 and the check works.

Problem 18: Find the mistake

Ones: \(7+5=12\), which is 1 ten and 2 ones. Noah did not add the new ten.

The correct sum is \(47+35=82\).

Problem 19: Fruit stand

\(38+45=83\). (Ones: 8 + 5 = 13. Tens: 3 + 4 + 1 = 8.)

The stand has 83 pieces of fruit.

Problem 20: Reading log

\(27+35=62\).

Maya read 62 pages.

Grade 2 Add Worksheet Answer Key: problems 21–24

Problem 21: Bake sale

\(24+18=42\), then \(42+23=65\).

The sale had 65 treats.

Problem 22: Library cart

\(17+26=43\), then \(43+31=74\).

The cart holds 74 books.

Problem 23: Sticker collection

\(56+28=84\), then \(84+9=93\).

Sofia has 93 stickers.

Problem 24: Field trip

\(39+47=86\), then \(86+12=98\).

98 students go. Yes, \(98 < 100\).

How to use this grade 2 add worksheet answer key

Read this grade 2 add worksheet answer key after trying each problem yourself, and redo any problem you missed.

See every chapter on the Grade 2 math page.