Practices pronunciation or spelling of numbers.
Japanese word: (数字, suuji)
Numbers are essential to learn and practice, but be aware of some challenging aspects of English numbers:
-teen words often sound very similar to -ty words. (fifteen versus fifty) The -n sound at the end of -teen words can be very subtle. The intonation can differ, but different dialects of English can have varying intonations in number words.
The words for large numbers in Japanese (and Korean) are based on the words from Chinese, where digits are separated in units of four. Digits are separated in units of three in English (like 3,000 or 4,100,591). Converting between the two can be a little confusing to do on the fly.