12 multiple-choice questions, progressively harder.
What is the principal (non-negative) square root 9\sqrt{9}9?
Solution
Correct answer: B
A square root asks what non-negative number squared gives the radicand.
32=9⇒9=33^2 = 9 \quad\Rightarrow\quad \sqrt{9} = 332=9⇒9=3
It is not 9÷2=4.59 \div 2 = 4.59÷2=4.5, and it is not 92=819^2 = 8192=81.
What is 16\sqrt{16}16?
Correct answer: A
Find the non-negative number that squares to 161616.
42=16⇒16=44^2 = 16 \quad\Rightarrow\quad \sqrt{16} = 442=16⇒16=4
It is not 16÷2=816 \div 2 = 816÷2=8.
What is 1\sqrt{1}1?
Correct answer: D
Look for the non-negative number whose square is 111.
12=1⇒1=11^2 = 1 \quad\Rightarrow\quad \sqrt{1} = 112=1⇒1=1
One is its own square, so its square root is 111.
What is 49\sqrt{49}49?
Find the non-negative number that squares to 494949.
72=49⇒49=77^2 = 49 \quad\Rightarrow\quad \sqrt{49} = 772=49⇒49=7
What is 0\sqrt{0}0?
Ask which number squared gives 000.
02=0⇒0=00^2 = 0 \quad\Rightarrow\quad \sqrt{0} = 002=0⇒0=0
Zero is the one radicand whose root needs no choice of sign.
What is 100\sqrt{100}100?
Find the non-negative number whose square is 100100100.
102=100⇒100=1010^2 = 100 \quad\Rightarrow\quad \sqrt{100} = 10102=100⇒100=10
What is 4\sqrt{4}4?
Correct answer: C
Find the non-negative number that squares to 444.
22=4⇒4=22^2 = 4 \quad\Rightarrow\quad \sqrt{4} = 222=4⇒4=2
Since 64=8\sqrt{64} = 864=8, what is 828^282?
Squaring and taking the square root are inverse operations, so squaring 888 undoes the root and returns the radicand.
82=648^2 = 6482=64
That is exactly the number whose square root was 888.
What is 144\sqrt{144}144?
Find the non-negative number whose square is 144144144.
122=144⇒144=1212^2 = 144 \quad\Rightarrow\quad \sqrt{144} = 12122=144⇒144=12
What is 81\sqrt{81}81?
Find the non-negative number that squares to 818181.
92=81⇒81=99^2 = 81 \quad\Rightarrow\quad \sqrt{81} = 992=81⇒81=9
What is 121\sqrt{121}121?
Find the non-negative number whose square is 121121121.
112=121⇒121=1111^2 = 121 \quad\Rightarrow\quad \sqrt{121} = 11112=121⇒121=11
What is 64\sqrt{64}64?
Find the non-negative number that squares to 646464.
82=64⇒64=88^2 = 64 \quad\Rightarrow\quad \sqrt{64} = 882=64⇒64=8
Reset this practice set?
This clears every answer you have given and starts the set again from question 1.