Learn · Mathematics · Class 2

Addition & Subtraction to 100

Adding and taking away bigger numbers, using tens and ones.

6 parts
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34 = 3 tens and 4 ones3 tens = 304 ones = 430 + 4 = 34
34 is 3 rods of ten and 4 single ones.
🧩 The partsAdding the easy wayPart 2 of 6
🔍 In detailTaking awayPart 3 of 6
✏️ Worked exampleCheck your answerPart 4 of 6
✅ SummaryNumber star!Part 5 of 6
✏️ Worked exampleWatch one worked throughPart 6 of 6
1📘 DefinitionPart 1 / 6

Tens and ones

Big numbers are made of tens and ones.

34 means 3 tens and 4 ones.

🎯 How many tens in 52?
2🧩 The partsPart 2 / 6

Adding the easy way

Add the tens first, then the ones.

23 + 15
20 + 10 = 30
3 + 5 = 8
30 + 8 = 38
🎯 20 + 30 = ?
3🔍 In detailPart 3 / 6

Taking away

Subtracting means taking some away.

The sign is −. Start with the big number and count back.

45 − 20 = 25
🎯 60 − 10 = ?
4✏️ Worked examplePart 4 / 6

Check your answer

Adding and subtracting are opposites. Use one to check the other!

If 30 + 12 = 42, then 42 − 12 must be 30. Try it!

🎯 25 + 10 = 35. So 35 − 10 = ?
5✅ SummaryPart 5 / 6

Number star!

  • Numbers are made of tens and ones.
  • Add the tens first, then the ones.
  • Adding and subtracting are opposites.
6✏️ Worked examplePart 6 / 6

Watch one worked through

Here is one done slowly, with the reason for every move. Then one for you.

Let me show you

What is 47 + 25?

  1. 47 + 25 → 47 + 20 + 5
    Split the second number: 25 is 20 and 5.
    Breaking a number into tens and ones makes it easy to add in two simple goes.
  2. 47 + 20 = 67
    Add the tens first: 47 + 20 = 67.
    Adding tens only changes the tens digit, so it is quick and hard to get wrong.
  3. 67 + 5 = 72
    Now add the ones: 67 + 5 = 72.
    This crosses into the next ten, which is the part to slow down for.

Answer: 72

Now you try

What is 38 + 24?

Show the answer

62

Practise Addition & Subtraction to 100

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🧠 6 quizzes on Addition & Subtraction to 100 (2 easy, 3 medium, 1 hard)

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🖨️ Printable worksheet

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