Pattern and place value

12345678
Across
  1. 4. A pattern that increasing by the same amount each time .
  2. 6. Rounding 245 to nearest hundred gives _____.
  3. 7. In 2877 8 is at which place .
  4. 8. The pattern 5,19,15,20 is a pattern of counting by ___.
Down
  1. 1. The sum of the digit of 421 is ____.
  2. 2. 200,300,400,500,____
  3. 3. Rounding 74 to nearest 10 gives ______.
  4. 5. A repeated design or sequence is called ______.