Estimate and place square roots and pi on a number line

Answer Key - Grade 8 Math Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. Read this first

   Use this

   Number line with a tick at every hundredth. Green marks are whole numbers, blue marks the other integers, orange marks the other rational numbers, and purple marks irrational numbers.

2. 1.

   Pia estimates √90 to the nearest hundredth. What is √90 to the nearest hundredth?

   9.49
3. 2.

   Ren rounds √35 to two decimal places. What is √35 to the nearest hundredth?

   5.92
4. 3.

   Ari cuts a square poster with an area of 94 square inches. About how long is each side, to the nearest tenth of an inch?

   9.7
6. 4.

   Bo plots a negative root. What is −√20 to the nearest tenth?

   -4.5
7. 5.

   Jun rounds a negative root on a calculator. What is −√31 to the nearest tenth?

   Use the picture in question 4.

   -5.6
9. 6.

   Kira squares the number π for a puzzle, and a pizza sits nearby. Between which two whole numbers is π²?

   • 9 and 10
   • 3 and 4
   • 10 and 11
   • 6 and 7
10. 7.

    Luz squares π on a calculator. Which whole number is π² closer to?

    Use the picture in question 6.

    • 9
    • 3
    • 10
    • 6
11. 8.

    Milo squares π with a coin in hand. Using π = 3.14, what is π² to the nearest tenth?

    • 6.3
    • 9.9
    • 9.8
    • 3.1
13. 9.

    Noah has a big square to place, √230. Between which two whole numbers is √230?

    • 14 and 15
    • 15 and 16
    • 16 and 17
    • 115 and 116
14. 10.

    Pia reads √300 on a calculator. Between which two whole numbers is √300?

    Use the picture in question 9.

    • 17 and 18
    • 18 and 19
    • 16 and 17
    • 150 and 151