2nd Grade Adding Within 100 Worksheet Solutions (PDF)

2nd Grade math worksheet solutions: Adding Within 100 – Maths PDF


This add within 100 answers for 2nd Grade covers adding within 100 (Common Core 2.NBT.B.5, 2.NBT.B.6), with a free PDF to print.

Add within 100 answers (2nd Grade) – first page of the printable PDF

Each answer shows the ones, then the tens, with any regrouping. Compare your work with these steps and fix any slips.

Grade 2 · Common Core State Standards: 2.NBT.B.5, 2.NBT.B.6

Add within 100 answers: exercises 1 to 10

Exercise 1 – Add tens

Ones: \(0 + 0 = 0\).

Tens: \(3 + 4 = 7\).

\(30 + 40 = 70\).

70

Exercise 2 – Blocks without regrouping

Ones: \(3 + 4 = 7\).

Tens: \(2 + 1 = 3\).

\(23 + 14 = 37\).

23+14=37
The sum is 3 tens and 7 ones.

37

Exercise 3 – Tens and ones

Ones: \(2 + 6 = 8\).

Tens: \(5 + 3 = 8\).

\(52 + 36 = 88\).

88

Exercise 4 – Add a group of tens

Ones: \(3 + 0 = 3\).

Tens: \(6 + 3 = 9\).

\(63 + 30 = 93\).

93

Exercise 5 – Add a one-digit number

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

Tens: \(4 + 0 + 1 = 5\) (with the regrouped ten).

\(47 + 6 = 53\).

53

Exercise 6 – First regrouping

Ones: \(8 + 5 = 13\), which is 1 ten and 3 ones.

Tens: \(2 + 1 + 1 = 4\) (with the regrouped ten).

\(28 + 15 = 43\).

tensones12815+43ones: 8 + 5 = 13tens: 1 + 2 + 1 = 4
Thirteen ones make 1 ten and 3 ones.

43

Exercise 7 – Regroup the ones

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

Tens: \(3 + 2 + 1 = 6\) (with the regrouped ten).

\(36 + 27 = 63\).

63

Exercise 8 – Bigger regrouping

Ones: \(9 + 4 = 13\), which is 1 ten and 3 ones.

Tens: \(4 + 3 + 1 = 8\) (with the regrouped ten).

\(49 + 34 = 83\).

83

Exercise 9 – Jumps on a number line

Hop 20 to 77. Then hop 5 to 82.

5060708090+20+582
Two hops from 57 land on 82.

\(57 + 25 = 82\). 82

Exercise 10 – Sum near ninety

Ones: \(8 + 9 = 17\), which is 1 ten and 7 ones.

Tens: \(6 + 1 + 1 = 8\) (with the regrouped ten).

\(68 + 19 = 87\).

87

Exercises 11 and up

Exercise 11 – Sum over ninety

Ones: \(4 + 8 = 12\), which is 1 ten and 2 ones.

Tens: \(7 + 1 + 1 = 9\) (with the regrouped ten).

\(74 + 18 = 92\).

92

Exercise 12 – Compare two sums

\(46 + 27 = 73\). \(39 + 36 = 75\). Since 75 is greater than 73, the second sum is greater.

\(39 + 36\) is greater

Exercise 13 – Missing digit

The ones must make a number that ends in 1. \(? + 7\) ends in 1 when \(4 + 7 = 11\). So the digit is 4.

Check: \(44 + 37 = 81\). 4

Exercise 14 – Break apart

\(54 + 20 = 74\). Then \(74 + 9 = 83\).

83

Exercise 15 – Three addends

Ones: \(2 + 5 + 1 = 8\).

Tens: \(1 + 2 + 3 = 6\).

\(12 + 25 + 31 = 68\).

tensones122531+68ones: 2+5+1 = 8tens: 1+2+3 = 6
No regrouping is needed.

68

Exercise 16 – Four addends

Ones: \(1 + 4 + 7 + 6 = 18\), which is 1 ten and 8 ones.

Tens: \(2 + 3 + 1 + 2 + 1 = 9\) (with the regrouped ten).

\(21 + 34 + 17 + 26 = 98\).

tensones121341726+98ones: 1+4+7+6 = 18tens: 2+3+1+2+1 = 9
Eighteen ones make 1 new ten.

98

Exercise 17 – Farmers market apples

Ones: \(7 + 8 = 15\), which is 1 ten and 5 ones.

Tens: \(4 + 3 + 1 = 8\) (with the regrouped ten).

\(47 + 38 = 85\).

854738
The total is 85.

Ana sold 85 apples.

Exercise 18 – Library cart

Ones: \(9 + 6 = 15\), which is 1 ten and 5 ones.

Tens: \(2 + 3 + 1 = 6\) (with the regrouped ten).

\(29 + 36 = 65\).

65 books

Exercise 19 – Little League runs

Ones: \(4 + 8 + 1 = 13\), which is 1 ten and 3 ones.

Tens: \(2 + 1 + 3 + 1 = 7\) (with the regrouped ten).

\(24 + 18 + 31 = 73\).

73 runs

Exercise 20 – Bake sale tables

Ones: \(5 + 2 + 8 + 6 = 21\), which is 2 tens and 1 ones.

Tens: \(1 + 2 + 1 + 2 + 2 = 8\) (with the regrouped tens).

\(15 + 22 + 18 + 26 = 81\).

81 muffins

Exercise 21 – Sticker collection

Step 1: \(56 + 27 = 83\).

Step 2: \(83 + 9 = 92\).

92 stickers

Exercise 22 – Can drive

Ones: \(8 + 5 + 7 = 20\), which is 2 tens and 0 ones.

Tens: \(4 + 3 + 1 + 2 = 10\) (with the regrouped tens).

\(48 + 35 + 17 = 100\).

Yes. They have exactly 100 cans.

Key facts behind this add within 100 answers

Key facts
  • Add ones first, then tens.
  • Ten ones can be regrouped as 1 ten: \(8 + 7 = 15\) is 1 ten and 5 ones.
  • On a number line, hop by tens and then by ones.
  • To add three or four numbers, add all the ones, then all the tens.
  • Estimating with tens helps you check an answer.

How to use this add within 100 answers

Cover each solution, solve the exercise again, then uncover it and compare every line. If your answer differs, find the first step that changed and redo the exercise from there.

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All Grade 2 chapters: Grade 2 math.

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