1.
Number of significant digits in 344.030
Correct Answer
D. Six
Explanation
The number 344.030 has six significant digits. Significant digits are the digits that carry meaning in a number and are not leading or trailing zeros. In this case, all the digits from 3 to 0 are significant, as they are not leading or trailing zeros. Therefore, the number has six significant digits.
2.
Number of significant digits in 55.40
Correct Answer
D. Four
Explanation
The number 55.40 has four significant digits. Significant digits are the digits in a number that carry meaning in terms of precision. In this case, the digits 5, 5, 4, and 0 are all significant because they all contribute to the precision of the number. The zero at the end is also significant because it indicates that the number is measured to the nearest tenth.
3.
Number of significant digits in 0.0041500
Correct Answer
E. Five
Explanation
The number 0.0041500 has five significant digits because all the zeros between the non-zero digits (4 and 1) are considered significant. The zeros after the last non-zero digit (0) are also significant because they are to the right of the decimal point.
4.
Number of significant digits in 2.04
Correct Answer
C. Three
Explanation
The number 2.04 has three significant digits because all non-zero digits are significant, and any zeros between non-zero digits are also significant. In this case, the digits 2, 0, and 4 are all non-zero, so they are all significant. There are no zeros between non-zero digits, so they are not significant. Therefore, the number 2.04 has three significant digits.
5.
Number of significant digits in 0.08
Correct Answer
A. One
Explanation
The number 0.08 has one significant digit because the first zero is not significant. In scientific notation, it would be written as 8 x 10^(-2), where the 8 is the only significant digit.
6.
Number of significant digits in 36
Correct Answer
B. Two
Explanation
The number 36 has two significant digits because both the digits, 3 and 6, are non-zero digits. Any non-zero digit is considered significant, and any leading or trailing zeros are not significant unless they are between two non-zero digits. In this case, there are no leading or trailing zeros, so only the 3 and 6 are significant.
7.
Number of significant digits in 450 cm when the ruler is precise to 1 cm
Correct Answer
C. Three
Explanation
The ruler is precise to 1 cm, meaning that it can measure up to the nearest centimeter. In the given measurement of 450 cm, all three digits (4, 5, and 0) are significant because they contribute to the overall value and precision of the measurement. Therefore, the number of significant digits in 450 cm is three.
8.
Round off 10.1 to a whole number.
Correct Answer
A. 10
Explanation
To round off 10.1 to a whole number, we look at the decimal place. Since the decimal is 0.1, which is less than 0.5, we round down to the nearest whole number. Therefore, the rounded off whole number for 10.1 is 10.
9.
Round off 119.357 to the tenths place.
Correct Answer
E. 119.4
Explanation
The correct answer is 119.4 because when rounding off to the tenths place, we look at the digit in the hundredths place, which is 5 in this case. Since 5 is greater than or equal to 5, we round up the digit in the tenths place, which is 9. Therefore, the number becomes 119.4.
10.
Round off 709 to the nearest ten's place.
Correct Answer
B. 710
Explanation
To round off 709 to the nearest ten's place, we look at the digit in the one's place. Since it is 9, which is greater than or equal to 5, we increase the digit in the ten's place by 1. Therefore, 709 rounds off to 710.
11.
Round 7.009 to three significant digits.
Correct Answer
C. 7.01
Explanation
The number 7.009 has four significant digits, but we need to round it to three significant digits. Since the next digit after the third significant digit (0) is 9, which is greater than or equal to 5, we round up the third significant digit (0) to 1. Therefore, the rounded number to three significant digits is 7.01.
12.
How many significant digits in 5.0000?
Correct Answer
E. Five
Explanation
The number 5.0000 has five significant digits because all the zeros after the decimal point are considered significant. In scientific notation, significant digits are used to represent the precision or accuracy of a number. In this case, the zeros indicate that the measurement or value is known to the fifth decimal place. Therefore, the answer is five.
13.
How many significant digits in 0.0010?
Correct Answer
B. Two
Explanation
The number 0.0010 has two significant digits, which are 1 and 0. The zeros before the 1 are not significant because they are leading zeros, and the zero after the decimal point is also not significant because it is a trailing zero. Therefore, the answer is two.
14.
Round off 600.9 to three significant digits.
Correct Answer
D. 601
Explanation
When rounding off to three significant digits, the first non-zero digit is considered. In this case, the non-zero digit is 6. The digit to the right of it is 0.9, which is greater than or equal to 5. Therefore, we round up the 6 to the next higher digit, which is 7. So, rounding off 600.9 to three significant digits gives us 601.
15.
Round off 7,877.0 to the nearest 100's place.
Correct Answer
A. 7,900
Explanation
To round off a number to the nearest 100's place, we look at the digit in the tens place. If it is 5 or greater, we round up. In this case, the digit in the tens place is 7, which is greater than 5. Therefore, we round up the number to the nearest hundred, which is 7,900.