1st Grade Adding and Subtracting Tens Within 100 Worksheet Solutions (PDF)
This adding tens answers for 1st Grade covers adding and subtracting tens within 100 (Common Core 1.NBT.C.4, 1.NBT.C.5, 1.NBT.C.6), with a free PDF to print.
Grade 1 · Common Core State Standards: 1.NBT.C.4, 1.NBT.C.5, 1.NBT.C.6
Adding tens answers: exercises 1 to 10
Exercise 1 – Count the blocks
Exercise 2 – 10 more
- 30
- 46
- 68
- 91
Exercise 3 – 10 less
- 30
- 42
- 57
- 80
Exercise 4 – Hundred chart
Exercise 5 – Add the ones
- \(30 + 4 = \)34
- \(50 + 7 = \)57
- \(23 + 4 = \)27
- \(56 + 3 = \)59
Exercise 6 – Blocks and more ones
Exercise 7 – Add tens
- \(20 + 30 = \)50 (2 tens + 3 tens = 5 tens)
- \(40 + 40 = \)80
- \(30 + 60 = \)90
- \(50 + 20 = \)70
Exercise 8 – Tens to a two-digit number
- \(34 + 20 = \)54
- \(41 + 30 = \)71
- \(26 + 50 = \)76
Exercise 9 – Subtract tens
- \(70 – 20 = \)50
- \(90 – 40 = \)50
- \(60 – 60 = \)0
- \(50 – 10 = \)40
Exercise 10 – Cross out the rods
Exercises 11 and up
Exercise 11 – Make the next ten
Exercise 12 – Make a ten
- \(47 + 3 = 50\), \(50 + 3 = 53\): 53
- \(35 + 5 = 40\), \(40 + 3 = 43\): 43
- \(59 + 1 = 60\), \(60 + 3 = 63\): 63
Exercise 13 – Missing number
- 30: 4 tens and 3 tens make 7 tens.
- 70: 7 tens and 2 tens make 9 tens.
- 50: 8 tens minus 5 tens is 3 tens.
- 40: 6 tens minus 4 tens is 2 tens.
Exercise 14 – Add in any order
- \(3 + 64 = \)67 (same as 64 + 3)
- \(70 + 15 = \)85
- \(20 + 58 = \)78
Exercise 15 – Cookie tray
Exercise 16 – Marbles
Exercise 17 – Cans for the food drive
Exercise 18 – Sticker book
Exercise 19 – Bags of oranges
Exercise 20 – Mystery number
Key facts behind this adding tens answers
- A two-digit number has tens and ones, like 34 = 3 tens and 4 ones.
- To add ones, keep the tens and add the ones.
- If the ones pass 9, make the next ten first.
- 10 more or 10 less changes only the tens digit.
- To subtract tens, think of tens: 8 tens – 3 tens = 5 tens.
How to use this adding tens 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.
All Grade 1 chapters: Grade 1 math.
