6th Grade Math Flashcards: Evaluate Expressions With Variables

What this deck covers

This deck focuses on Evaluate Expressions With Variables, giving you a quick way to review the definitions, rules, and examples that matter most for 6th Grade Math.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What is the value of $2x^2$ when $x=-3$?

Answer: $18$. $2(-3)^2 = 2(9) = 18$

Flashcard 2: What is the value of $\frac{n - 1}{3}$ when $n = 10$?

Answer: $3$. Substitute $n = 10$: $\frac{10 - 1}{3} = \frac{9}{3} = 3$.

Flashcard 3: What is the value of $7+3(x-4)$ when $x=4$?

Answer: $7$. $7+3(4-4) = 7+3(0) = 7+0 = 7$

Flashcard 4: What is the value of rac{1}{2}bh when $b = 8$ and $h = 5$?

Answer: $20$. This is the area formula for a triangle: rac{1}{2} imes 8 imes 5 = 20.

Flashcard 5: What is the value of $5(a - 2)$ when $a = 9$?

Answer: $35$. Substitute $a = 9$: $5(9 - 2) = 5(7) = 35$.

Flashcard 6: What is the value of $4y - 3(y - 2)$ when $y = 5$?

Answer: $11$. Substitute $y = 5$: $4(5) - 3(5 - 2) = 20 - 3(3) = 20 - 9 = 11$.

Flashcard 7: What is the value of $3x + 5$ when $x = 4$?

Answer: $17$. Replace $x$ with $4$: $3(4) + 5 = 12 + 5 = 17$.

Flashcard 8: What is the value of $7 - (2t - 5)$ when $t = 6$?

Answer: $0$. Substitute $t = 6$: $7 - (2(6) - 5) = 7 - (12 - 5) = 7 - 7 = 0$.

Flashcard 9: What does it mean to evaluate an expression such as $3x+2$ when $x=5$?

Answer: Substitute $x=5$ and simplify to get a number. Replace the variable with its given value and calculate.

Flashcard 10: What is the value of $a^2-b$ when $a=5$ and $b=12$?

Answer: $13$. $5^2-12 = 25-12 = 13$

Flashcard 11: What is the value of $3^2 + x$ when $x = 4$?

Answer: $13$. Substitute $x = 4$: $3^2 + 4 = 9 + 4 = 13$.

Flashcard 12: What is the value of rac{x+5}{2} when $x=7$?

Answer: $6$. rac{7+5}{2} = rac{12}{2} = 6

Flashcard 13: What is the value of $3x+2$ when $x=5$?

Answer: $17$. $3(5)+2 = 15+2 = 17$

Flashcard 14: What does it mean to evaluate an expression at $x = 4$?

Answer: Substitute $4$ for $x$ and compute the value. Replace the variable with the given number in the expression.

Flashcard 15: What is the distance $d = 60h$ miles when $h = 2.5$ hours?

Answer: $150$. Substitute $h = 2.5$: $d = 60(2.5) = 150$ miles.

Flashcard 16: What is the total cost $C = 2.5t + 4$ dollars when $t = 6$?

Answer: $19$. Substitute $t = 6$: $C = 2.5(6) + 4 = 15 + 4 = 19$ dollars.

Flashcard 17: What is the value of $2(x + 4) - x$ when $x = 7$?

Answer: $15$. Substitute $x = 7$: $2(7 + 4) - 7 = 2(11) - 7 = 22 - 7 = 15$.

Flashcard 18: What is the value of $2(3x + 1)$ when $x = 2$?

Answer: $14$. Substitute $x = 2$: $2(3(2) + 1) = 2(6 + 1) = 2(7) = 14$.

Flashcard 19: What is the value of $2x + 3x$ when $x = 6$?

Answer: $30$. Substitute $x = 6$: $2(6) + 3(6) = 12 + 18 = 30$.

Flashcard 20: What is the value of $3(x + 4) - 2$ when $x = 1$?

Answer: $13$. First add: $1 + 4 = 5$, multiply by $3$ to get $15$, then subtract $2$.

Flashcard 21: What is the value of 12(x-1) when $x=4$?

Answer: $36$. $12(4-1) = 12(3) = 36$

Flashcard 22: What is the value of rac{x}{3} + 2 when $x = 9$?

Answer: $5$. Calculate rac{9}{3} = 3, then add $2$ to get $5$.

Flashcard 23: What is the value of $2p+3q$ when $p=4$ and $q=1$?

Answer: $11$. $2(4)+3(1) = 8+3 = 11$

Flashcard 24: What is the value of $(x + 1)^2$ when $x = 3$?

Answer: $16$. First add: $3 + 1 = 4$, then square to get $16$.

Flashcard 25: What is the value of $\frac{3}{4}k$ when $k = 8$?

Answer: $6$. Substitute $k = 8$: $\frac{3}{4}(8) = \frac{24}{4} = 6$.

Flashcard 26: What is the value of rac{3}{4}n when $n=20$?

Answer: $15$. rac{3}{4}(20) = rac{60}{4} = 15

Flashcard 27: What is the value of $-3x + 2$ when $x = 4$?

Answer: $-10$. Multiply first: $-3(4) = -12$, then add $2$ to get $-10$.

Flashcard 28: What is the value of $-3a + 4$ when $a = 5$?

Answer: $-11$. Substitute $a = 5$: $-3(5) + 4 = -15 + 4 = -11$.

Flashcard 29: What is the value of $6 - (2x + 1)$ when $x = 2$?

Answer: $1$. Calculate inside parentheses first: $2(2) + 1 = 5$, then $6 - 5 = 1$.

Flashcard 30: What is the correct order of operations used when evaluating expressions?

Answer: Parentheses, exponents, multiply/divide, add/subtract. Remember PEMDAS: operations are performed in this specific sequence.

Flashcard 31: What order of operations should you use to evaluate an expression with variables?

Answer: Parentheses, exponents, multiplication/division, addition/subtraction. PEMDAS ensures consistent evaluation of expressions.

Flashcard 32: What is the value of $18 \div (n + 2)$ when $n = 4$?

Answer: $3$. Substitute $n = 4$: $18 \div (4 + 2) = 18 \div 6 = 3$.

Flashcard 33: What is the value of $2a + 3b$ when $a = 1$ and $b = 4$?

Answer: $14$. Substitute both values: $2(1) + 3(4) = 2 + 12 = 14$.

Flashcard 34: What is the value of $6-2(1-k)$ when $k=-2$?

Answer: $0$. $6-2(1-(-2)) = 6-2(3) = 6-6 = 0$

Flashcard 35: What is the value of $5(a - 2)$ when $a = 7$?

Answer: $25$. First find $a - 2 = 7 - 2 = 5$, then multiply by $5$.

Flashcard 36: What is the distance $d = 60t$ traveled in $t = 2.5$ hours?

Answer: $150$. Use distance formula: speed times time equals $60 imes 2.5 = 150$.

Flashcard 37: What is the value of $2p^2$ when $p = 3$?

Answer: $18$. Substitute $p = 3$: $2(3)^2 = 2(9) = 18$.

Flashcard 38: What is the value of $12 - 2y$ when $y = 3$?

Answer: $6$. Replace $y$ with $3$: $12 - 2(3) = 12 - 6 = 6$.

Flashcard 39: What is the value of $2(a+3)$ when $a=4$?

Answer: $14$. $2(4+3) = 2(7) = 14$

Flashcard 40: What is the value of $x^2 - 1$ when $x = 6$?

Answer: $35$. Square $6$ to get $36$, then subtract $1$.

Flashcard 41: What is the value of $5x - 2$ when $x = 0$?

Answer: $-2$. Substitute $x = 0$: $5(0) - 2 = 0 - 2 = -2$.

Flashcard 42: What is the value of $2^n$ when $n = 5$?

Answer: $32$. Calculate $2^5 = 2 imes 2 imes 2 imes 2 imes 2 = 32$.

Flashcard 43: What is the value of $3(m-2)+5$ when $m=2$?

Answer: $5$. $3(2-2)+5 = 3(0)+5 = 0+5 = 5$

Flashcard 44: What is the value of $12 - 2n$ when $n = 7$?

Answer: $-2$. Substitute $n = 7$: $12 - 2(7) = 12 - 14 = -2$.

Flashcard 45: What is the value of $2q(1 + q)$ when $q = 3$?

Answer: $24$. Substitute $q = 3$: $2(3)(1 + 3) = 2(3)(4) = 24$.

Flashcard 46: What is the total cost $C=2.50n$ when $n=6$ items are purchased?

Answer: $15$. $C = 2.50(6) = 15$ dollars for 6 items.

Flashcard 47: What is the value of $4-(2t-1)$ when $t=3$?

Answer: $-1$. $4-(2(3)-1) = 4-(6-1) = 4-5 = -1$

Flashcard 48: What is the value of $2(x - 3)^2$ when $x = 5$?

Answer: $8$. First find $5 - 3 = 2$, square to get $4$, then multiply by $2$.

Flashcard 49: What is the value of $5-y^2$ when $y=3$?

Answer: $-4$. $5-3^2 = 5-9 = -4$

Flashcard 50: What is the value of rac{2}{3}x+4 when $x=9$?

Answer: $10$. rac{2}{3}(9)+4 = 6+4 = 10

Flashcard 51: What is the value of $6 + \, \frac{m}{2}$ when $m = 10$?

Answer: $11$. Substitute $m = 10$: $6 + \frac{10}{2} = 6 + 5 = 11$.

Flashcard 52: What is the distance $d=60t$ after t=rac{1}{2} hour at $60$ miles per hour?

Answer: $30$. d = 60(rac{1}{2}) = 30 miles traveled in half an hour.

Flashcard 53: What is the total cost $C = 2.50n$ for $n = 6$ items?

Answer: $15$. Multiply unit price by quantity: $2.50 imes 6 = 15$.

Flashcard 54: What is the value of $4 + 3x^2$ when $x = 2$?

Answer: $16$. First square $2$ to get $4$, multiply by $3$, then add $4$.