Adding tens

30 + 40: count the tens.

🔍 Step 1 · Understand

First, look at a worked example

40 + 50 = ?

💡 The tip : 40 is 4 tens, and 50 is 5 tens.

🤔 Find the answer in your head, then open the solution.

👀 See the solution

Answer: 90

4 tens + 5 tens = 9 tens, so 40 + 50 = 90.

10 questions. Take your time, and ask for a hint if you get stuck.