Numbers, numbers, numbers!
Who can say it's not important. We use them in our lives daily, most of the time we don't even realize it. Think about going grocery shopping, taking measurements, following recipes, reading time, or calculating age. Because numbers are so important, it's crucial we know how to pronounce them correctly and be able to hear the differences between different numbers.
One of the most commonly mispronunced are the teen and ten numbers. Many times a number like 18 could be heard as 80. These are sometimes hard to distinguish and even native speakers may ask for verification.
Practice with these:
The "ty" in the number seventy when spoken in American English gives off a 'd' sound.
Also, pay attention to where the stress is ( the part in red). The teen numbers are stressed in the "teen" and the ten numbers are stressed in the first number part.
If you still need more practice, try listening to spoken numbers from the website below, remember what you learned from the guide above and practice, practice, practice!