2100
The greatest place value will be whatever non-zero digit is farthest to the left. Look at the digit immediately to the right of it. If that digit is four or less, zero it and everything to the right of it out. If that digit is five or higher, increase the greatest digit by one and zero everything to the right of it out.
600 same as rounding to 1 significant figure
No, 6. You count from the first non-zero digit to the last non-zero digit. Zeros between non-zero digits are counted.
millions
2100
129,000
Round it to the nearest thousand, which is 7,000 .
Round to whatever non-zero digit is farthest to the left.
It is 5000000.
Round it to the nearest ten thousands: 90000
Round to the nearest million and get 6 000 000
The greatest place value will be whatever non-zero digit is farthest to the left. Look at the digit immediately to the right of it. If that digit is four or less, zero it and everything to the right of it out. If that digit is five or higher, increase the greatest digit by one and zero everything to the right of it out.
600 same as rounding to 1 significant figure
4 Every digit between the leftmost non-zero digit and EITHER the right most non-zero digit OR the rightmost digit after a decimal.
No, 6. You count from the first non-zero digit to the last non-zero digit. Zeros between non-zero digits are counted.
To correct to 4 significant figures, you need to round the number to have four digits starting with the first non-zero digit from the left. If the fifth digit is 5 or more, round up the last remaining digit. If it's less than 5, keep the digit as it is.