ISAT Grade 8 The Number System. Practice it free.

Works with rational and irrational numbers and numerical approximations. This Grade 8 reporting domain maps to 7 practice skills and 8 representative questions from the playable bank.

Grade 87 mapped skills
What the test measures

The Number System skills

  1. Know that there are numbers that are not rational, and approximate them by rational numbers

  2. Work with radicals and integer exponents

  3. Use square root and cube root symbols to represent solutions to equations of the form x^2 = p and x^3 = p

Standards basis

Idaho Content Standards (Mathematics) — Idaho

How the ISAT reports it

Idaho ISAT is a state assessment administered to grades 3–8 and 11 and reported against Idaho grade-level content standards rather than a separate national testing framework. The public ISAT page points to summative blueprints and math specifications, while the Idaho Content Standards page shows the math program is organized by grade-band/domain progressions aligned to Idaho standards.

Blueprint & weighting

The public Idaho ISAT page references summative blueprints and item specifications, but the accessible official page content did not expose a published domain-by-domain percentage blueprint for math.

Try it now

8 free questions · 0/0 correct

Practice playeasy

Solve for all values of x.x\textsf{.}

x3=−64x^{3} = -64

(−4)×(−4)×(−4)=−64,(-4) \times (-4) \times (-4) = -64\textsf{,} so x=−4.x = -4\textsf{.}

Practice playeasy

Evaluate 1253.\sqrt[\text{\scriptsize 3}]{125}\textsf{.}

5×5×5=125,5 \times 5 \times 5 = 125\textsf{,} so 1253=5.\sqrt[\text{\scriptsize 3}]{125} = 5\textsf{.}

Practice playeasy

27⋅2426=2n.\dfrac{2^{7} \cdot 2^{4}}{2^{6}} = 2^{n}\textsf{.} What is n?n\textsf{?}

The Product of Powers Property says that powers with the same base are multiplied by adding the exponents, written xm⋅xn=xm+n.x^{m} \cdot x^{n} = x^{m+n}\textsf{.} The numerator is 27⋅24=27+4=211.2^{7} \cdot 2^{4} = 2^{7+4} = 2^{11}\textsf{.} The Quotient of Powers Property then subtracts the exponents of powers with the same base, written xmxn=xm−n.\dfrac{x^{m}}{x^{n}} = x^{m-n}\textsf{.} So 21126=211−6=25\dfrac{2^{11}}{2^{6}} = 2^{11-6} = 2^{5} and n=5.n = 5\textsf{.}

Practice playmedium

Let f(t)=8e3t+50f(t) = 8e^{3t} + 50. Which of the following approximations, written as a×10na \times 10^n with one significant digit, is closest to the value of f(2)f(2)?

Substitute t=2t = 2: f(2)=8e6+50f(2) = 8e^{6} + 50. Since e6≈403.4e^{6} \approx 403.4, f(2)≈8(403.4)+50=3,277≈3×103f(2) \approx 8(403.4) + 50 = 3{,}277 \approx 3 \times 10^{3}.

Practice playeasy

Which expression is 0.00750.0075 in scientific notation?

Moving the decimal in 0.00750.0075 three places right gives 7.5×10−3.7.5 \times 10^{-3}\textsf{.}

Practice playeasy

What is (3×102)(3×103)(3 \times 10^{2})(3 \times 10^{3}) in scientific notation?

Coefficients multiply to 9;9\textsf{;} exponents add: 2+3=5.2 + 3 = 5\textsf{.} So (3×102)(3×103)=9×105.(3 \times 10^{2})(3 \times 10^{3}) = 9 \times 10^{5}\textsf{.}

Practice playeasy

What is the integer part of 10+2\sqrt{10} + 2?

10≈3.16\sqrt{10} \approx 3.16, so 10+2≈5.16\sqrt{10} + 2 \approx 5.16; the integer part is 55.

Practice playeasy

Solve for all values of x.x\textsf{.}

x2=196x^{2} = 196

14×14=19614 \times 14 = 196 and (−14)×(−14)=196,(-14) \times (-14) = 196\textsf{,} so x=±14.x = \pm 14\textsf{.}

Keep practicing

Turn the number system into game time.

The ISAT placement starts with this test's real coverage map and finds the right difficulty.