Here are the solutions for rounding each number to the specified significant figures.
1) 2.3609
*
a) Round to 1 significant digit: Look at the first digit (2). The next digit is 3, which is less than 5, so we keep the 2 as it is.
* Answer:
2
*
b) Round to 2 significant digits: Look at the first two digits (2.3). The next digit is 6, which is 5 or greater, so we round the 3 up to 4.
* Answer:
2.4
*
c) Round to 3 significant digits: Look at the first three digits (2.36). The next digit is 0, which is less than 5, so we keep the 6 as it is.
* Answer:
2.36
2) 578.2194
*
a) Round to 2 significant digits: Look at the first two digits (57). The next digit is 8, which is 5 or greater, so we round the 7 up to 8. Replace the remaining whole number places with zeros.
* Answer:
580
*
b) Round to 5 significant digits: Look at the first five digits (578.21). The next digit is 9, which is 5 or greater, so we round the 1 up to 2.
* Answer:
578.22
*
c) Round to 1 significant digit: Look at the first digit (5). The next digit is 7, which is 5 or greater, so we round the 5 up to 6. Replace the remaining whole number places with zeros.
* Answer:
600
3) 7.3482
*
a) Round to 2 significant digits: Look at the first two digits (7.3). The next digit is 4, which is less than 5, so we keep the 3 as it is.
* Answer:
7.3
*
b) Round to 3 significant digits: Look at the first three digits (7.34). The next digit is 8, which is 5 or greater, so we round the 4 up to 5.
* Answer:
7.35
*
c) Round to 4 significant digits: Look at the first four digits (7.348). The next digit is 2, which is less than 5, so we keep the 8 as it is.
* Answer:
7.348
4) 41.095
*
a) Round to 2 significant digits: Look at the first two digits (41). The next digit is 0, which is less than 5, so we keep the 1 as it is.
* Answer:
41
*
b) Round to 3 significant digits: Look at the first three digits (41.0). The next digit is 9, which is 5 or greater, so we round the 0 up to 1.
* Answer:
41.1
*
c) Round to 1 significant digit: Look at the first digit (4). The next digit is 1, which is less than 5, so we keep the 4 as it is. Replace the remaining whole number place with a zero.
* Answer:
40
5) 1254.33
*
a) Round to 4 significant digits: Look at the first four digits (1254). The next digit is 3, which is less than 5, so we keep the 4 as it is.
* Answer:
1254
*
b) Round to 1 significant digit: Look at the first digit (1). The next digit is 2, which is less than 5, so we keep the 1 as it is. Replace the remaining whole number places with zeros.
* Answer:
1000
*
c) Round to 3 significant digits: Look at the first three digits (125). The next digit is 4, which is less than 5, so we keep the 5 as it is. Replace the remaining whole number place with a zero.
* Answer:
1250
Final Answer:
1) a) 2, b) 2.4, c) 2.36
2) a) 580, b) 578.22, c) 600
3) a) 7.3, b) 7.35, c) 7.348
4) a) 41, b) 41.1, c) 40
5) a) 1254, b) 1000, c) 1250
Parent Tip: Review the logic above to help your child master the concept of significant figures worksheet.
