Count to 120

Grade 1 · mathematics · 99 practice problems · read aloud

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Count to 120

What is Counting and Why is it Useful? 🧮

Counting to 120 is all about saying numbers in the right order. It's like a superpower for math! You use it to know how many cookies you have, to play board games, and to get ready for adding and subtracting.

How to Count to 120

  1. Start at 1: Begin with "one" and go up: 1, 2, 3, 4, 5...
  2. Master the Pattern: After 9 comes 10. After 19 comes 20. The pattern repeats all the way to 99!
  3. Reach 100 and Beyond: After 99 comes 100. Then keep going: 101, 102, 103... all the way to 120!

Let's Look at Some Examples

Example 1: What comes after 29?

We know the pattern: after 9 comes 10, after 19 comes 20. So, after 29 comes 30!

Example 2: Count from 115 to 120.

115... 116... 117... 118... 119... 120! You made it!

Watch Out for These Common Mistakes!

  • The "Teen" Trap: It's four-TEEN (14), then fif-TEEN (15). Don't mix them up!
  • The Jump to 100: After 99, the next number is 100, not 1000. Think of it as a big celebration for reaching one hundred!
  • Confusing Numbers: It's one hundred ONE (101), not "one hundred and one."

Tips & Tricks to Be a Counting Champion

  • Use a 120 chart to see all the numbers at once.
  • Count groups of objects, like your toys or crayons.
  • Look for patterns. All the numbers in the 20s column start with "twenty-".
  • Sing counting songs or rhymes! 🎵

How to Practice

You can practice counting anywhere!

  • Count your steps as you walk.
  • Count how many bites it takes to eat your snack.
  • Ask a grown-up to point to a number on a chart, and you say what comes next.
  • Try writing the numbers from 1 to 120 on a big piece of paper.

Practice problems

6 of the 99, worked through step by step — try them before opening the answer.

1 15 + 7 = ?

Hint: Start with the larger number and count up the smaller number.

Show the answer

Answer: 22

  1. Write the numbers vertically in your mind to align by place value. 15 + 7 --- ?
  2. Add the digits in the ones column first. The ones column has 5 (from 15) and 7 (from 7). 5 + 7 = 12.
  3. Since 12 is a two-digit number, we split it: 12 = 10 + 2. We write 2 in the ones place of the answer and carry over 1 to the tens column.
  4. Now add the tens column. The tens column of 15 has 1, and there is no tens digit in 7, but we have the carried-over 1 from
  5. So: 1 (from 15) + 0 (from 7) + 1 (carried over) = 2.
  6. Write 2 in the tens place of the answer.
  7. Combine the tens digit and ones digit: 2 (tens) and 2 (ones) gives 22. Therefore, 15 + 7 = 22.

We are adding 15 and 7.

2 75 + 45 = ?

Hint: Think about adding the tens first, then the ones, and then combining them.

Show the answer

Answer: 120

  1. Write the numbers vertically, aligning them by place value (ones and tens). 75 + 45
  2. Add the digits in the ones column first. Ones column: 5 + 5 = 10. 10 ones means 1 ten and 0 ones. Write down the 0 in the ones place of the answer, and carry over the 1 ten to the tens column. 75 + 45 -- 0 (carry 1)
  3. Now add the digits in the tens column, including the carry-over. Tens column: 7 + 4 + 1 (carry) = 12. 12 tens means 120. Write down 12 in the tens/hundreds place of the answer. 75 + 45 --- 120
  4. Interpret the result. 12 tens and 0 ones is 120. Final Answer: 120

Let's add 75 and 45 step-by-step.

3 25 + 17 = ?

Hint: Start by adding the numbers in the ones place first, then add the numbers in the tens place.

Show the answer

Answer: 42

  1. Write the numbers vertically, aligning the ones and tens places. 25 + 17
  2. Add the digits in the ones column (rightmost column). 5 + 7 = 12
  3. Since 12 is a two-digit number, we separate it into 10 and 2. We write down the 2 in the ones place of the answer and carry over the 1 (which represents 10) to the tens column.
  4. Now add the digits in the tens column, including the carry-over. 2 + 1 + 1 = 4 (The 2 is from 25, the 1 is from 17, and the last 1 is the carry-over from the ones column.)
  5. Write the result from the tens column next to the 2 from the ones column.

Let's add 25 and 17 step-by-step. The answer is 42. So, 25 + 17 = 42.

4 45 + 23 = ?

Hint: Think about adding the tens first, then the ones.

Show the answer

Answer: 68

  1. Write the numbers vertically, aligning the ones and tens columns. 45 + 23
  2. Add the digits in the ones column first. 5 (ones from 45) + 3 (ones from 23) = 8 Write 8 in the ones place of the answer.
  3. Add the digits in the tens column. 4 (tens from 45) + 2 (tens from 23) = 6 Write 6 in the tens place of the answer.
  4. Combine the results from the tens and ones columns. The tens column gave 6, and the ones column gave 8, so together they make 68. Therefore, 45 + 23 = 68.

Let's add 45 and 23 step-by-step.

5 45 + 35 = ?

Hint: Think about adding the tens first, then the ones.

Show the answer

Answer: 80

  1. Write the numbers vertically, aligning the digits by place value (ones and tens). 45 + 35
  2. Add the digits in the ones column (rightmost column). 5 (from 45) + 5 (from 35) = 10.
  3. Since 10 is a two-digit number, we separate it into 10 ones. 10 ones = 1 ten and 0 ones. Write down the 0 in the ones place of the answer, and carry over the 1 ten to the tens column.
  4. Now add the digits in the tens column, including the carry-over. 4 (from 45) + 3 (from 35) + 1 (carried over) = 8.
  5. Write the 8 in the tens place of the answer.
  6. Combine the tens and ones digits: 8 tens and 0 ones is 80. Therefore, 45 + 35 = 80.

Let's add 45 and 35 step by step.

6 25 + 15 = ?

Hint: Think about combining two groups of tens and ones.

Show the answer

Answer: 40

  1. Write the problem clearly. 25 + 15
  2. Start by adding the numbers in the ones place (the rightmost digits). The ones digit of 25 is 5. The ones digit of 15 is 5. Add them: 5 + 5 = 10.
  3. Handle the result from
  4. Since 10 is a two-digit number, we write down the 0 in the ones place of the answer and carry over the 1 to the tens place.
  5. Now add the numbers in the tens place, including the carry-over. The tens digit of 25 is 2. The tens digit of 15 is 1. Add them: 2 + 1 = 3. Now add the carried-over 1: 3 + 1 = 4.
  6. Combine the results. The tens place is 4 and the ones place is 0. So the final answer is 40. Therefore, 25 + 15 = 40.

Let's add 25 and 15 step-by-step.

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