Number bonds to 10 and 100 — Mental Maths Mastery

How to do it in your head

Make 10 — “know which pairs fill up a ten or a hundred”

1. Bonds to 10: 1 + 9, 2 + 8, 3 + 7, 4 + 6, 5 + 5.
2. Bonds to 100: the ones make 10, and the tens make 9 (because the ones already gave one ten).
3. If the number ends in 0, the tens make 10: 40 + 60 = 100.

Use it for: Giving change from ₹10 or ₹100, finishing a ten while adding, and checking subtraction.

Worked example: 64 + ? = 100 → 36

✏️ Practice

Work it out in your head or on paper, then tap your answer — or type it and press Check. Stuck? Press “Show me how”.

🏁 Lesson 1 test

20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.

🏅 Sign in with Google to earn the 🤝 Bond Builder badge when you pass — and a certificate when you finish all 7 lessons of Part 1 · Mental addition & subtraction. You can still take the test without signing in.

🖨️ Number Bonds Worksheet (to 10 and 100)

• Worksheet set 1 (PDF)
• Worksheet set 2 (PDF)
• Worksheet set 3 (PDF)