423.0
400
420
To round 423 to the nearest ten, we look at the digit in the tens place, which is 2. Since the digit to the right of it is 3, which is 5 or greater, we round up. Therefore, 423 rounded to the nearest ten is 430.
400
Yes
400
2,900,000
1, 3, 9, 47, 141, 423
423 is a composite number. Its prime factorisation is 3 x 3 x 47.
I put the larger number above the smaller number and then I subtract. 719 423 ----- 296
No, it is not a prime number.