Numbers and the four operations
- 1.In the number 2,853,719, what is the 5 worth?
- 2.7,003 − 2,548 =
- 3.27 × 35 =
- 4.20 − 2 × (9 − 3) ÷ 4 =
Signed Numbers (positives & negatives)
- 5.−8 + 15 =
- 6.3 − (−9) =
- 7.−7 × (−6) =
Fractions
- 8.35 + 14 =
- 9.23 × 38 =
- 10.34 ÷ 18 =
- 11.Which is larger: 23 or 710?
Decimals
- 12.9.2 − 4.65 =
- 13.0.8 × 0.45 =
- 14.Write 58 as a decimal.
- 15.A storage locker costs $23.75 a month. What do twelve months cost?
Percents, ratios, and proportion
- 16.What is 35% of 80?
- 17.A $60 backpack is marked 30% off. What is the sale price?
- 18.What is 12 out of 40 as a percent?
- 19.A car uses 4 gallons of gas to go 130 miles. How far can it go on 10 gallons?
Measurement and units
- 20.How many ounces are in 6 pounds?
- 21.A cooler holds 5 gallons of water. How many quarts is that?
- 22.A table is 3 feet 4 inches long. How many inches is that?
Geometry
- 23.A triangle has a base of 12 inches and a height of 7 inches. What is its area?
- 24.A circle has a radius of 5 cm. What is its area? Use 3.14 for π.
- 25.A right triangle has legs of 5 and 12. How long is the hypotenuse?
- 26.Two lines cross. One of the four angles is 48°. What is the angle directly opposite it?
- 27.A box is 8 inches long, 5 inches wide, and 4 inches tall. What is its volume?
- 28.A can has a radius of 2 inches and a height of 10 inches. What is its volume? Use 3.14 for π.
Data, graphs, and statistics
- 29.Cups of coffee sold at the cart
How many more cups were sold on Thursday than on Tuesday?Day Cups Monday 62 Tuesday 45 Wednesday 58 Thursday 71 - 30.Find the mean of 15, 9, 13, 11.
- 31.Find the median of 14, 6, 10, 3, 9.
- 32.Find the range of 27, 8, 19, 12.
Probability and counting
- 33.A box holds 2 red pens, 6 blue, and 4 black. You take one without looking. What is the probability it is black?
- 34.The forecast says there is a 45% chance of snow. What is the probability it does not snow?
- 35.A food cart offers 5 kinds of rice bowl and 4 drinks. How many different bowl-and-drink combinations can be ordered?
Exponents, roots, and scientific notation
- 36.53 =
- 37.√144 =
- 38.Write as a single power: x4 × x5
- 39.What is 120?
- 40.Write 45,000,000 in scientific notation.
Expressions and polynomials
- 41.Simplify: 7x − 4 + 2x + 9
- 42.Multiply out: 5(3x − 2)
- 43.Multiply out: (x + 2)(x − 5)
Equations and inequalities
- 44.Solve for x: 4x + 5 = 33
- 45.Solve for x: 8x − 9 = 5x + 15
- 46.Solve: 3x + 4 < 19
- 47.An electrician charges $75 to come out, plus $40 an hour. The bill came to $315. How many hours did the job take?
Lines, slope, and systems
- 48.What is the slope of the line through (1, 2) and (5, 14)?
- 49.For the line y = 2x − 7, what are the slope and the y-intercept?
- 50.The line passes through the two marked points. What is its slope?
- 51.Solve the system: x + y = 15 and x − y = 3
Functions and the coordinate plane
- 52.If f(x) = 3x + 4, what is f(6)?
- 53.If f(x) = 5x − 8, for which x is f(x) = 27?
- 54.What are the coordinates of point B?
- 55.What is the midpoint of the segment from A (−4, 1) to B (2, 5)?
Or check one family at a time, with the button under it.
Where to go next
| Family | Questions | Right | Where to go next | Practice |
|---|---|---|---|---|
| 1. Numbers and the four operations | 1–4 | of 4 | Go to Numbers and the four operationsseven quizzes, the times tables, and what to look up elsewhere | |
| 2. Signed numbers | 5–7 | of 3 | Go to Signed Numbers (positives & negatives)three quizzes, Negative Mazarine!, and Diagnostic 2 | |
| 3. Fractions | 8–11 | of 4 | Go to Fractionsfive quizzes, and Diagnostic 1 for a closer look | |
| 4. Decimals | 12–15 | of 4 | Go to Decimalsfour quizzes, and Diagnostic 1 for a closer look | |
| 5. Percents, ratios, and proportion | 16–19 | of 4 | Go to Percents, ratios, and proportionsix quizzes, in two legs | |
| 6. Measurement and units | 20–22 | of 3 | Go to Measurement and unitsQuiz 26, and what to look up elsewhere | |
| 7. Geometry | 23–28 | of 6 | Go to GeometryQuiz 27, Circles and Equations, The Third Side, and Diagnostic 3 | |
| 8. Data, graphs, and statistics | 29–32 | of 4 | Go to Data, graphs, and statisticsQuiz 28, and what to look up elsewhere | |
| 9. Probability and counting | 33–35 | of 3 | Go to Probability and countingnothing written for it yet — the page says where to go meanwhile | |
| 10. Exponents, roots, and scientific notation | 36–40 | of 5 | Go to Exponents, roots, and scientific notationfive quizzes, two apps, and a chart to print | |
| 11. Expressions and polynomials | 41–43 | of 3 | Go to Expressions and polynomialsLike With Like, and Diagnostic 3 | |
| 12. Equations and inequalities | 44–47 | of 4 | Go to Equations and inequalitiesthree rooms, a practice sheet, and Diagnostic 3 | |
| 13. Lines, slope, and systems | 48–51 | of 4 | Go to Lines, slope, and systemsLines on the Grid, and Diagnostic 3 | |
| 14. Functions and the coordinate plane | 52–55 | of 4 | Go to Functions and the coordinate planeLines on the Grid, and Diagnostic 3 |
The quiz series is at thepeoplesshare.org/ged/math.
The key prints only when it is showing, and it starts on its own page. After you check a family, each question you missed offers its own reasoning with the Why? button.
Answers, with the reasoning in brief
- 1.50,000. The 5 stands in the ten-thousands place, so it is worth fifty thousand. Count the places from the right to see it: 9 ones, 1 ten, 7 hundreds, 3 thousands, 5 ten-thousands. The whole number reads: two million, eight hundred fifty-three thousand, seven hundred nineteen.
- 2.4,455. You cannot take 8 from 3, and the tens and hundreds are zeros, so the borrow comes all the way from the thousands: 7,003 becomes 6 thousands, 9 hundreds, 9 tens, and 13 ones. Then 13 − 8 = 5, 9 − 4 = 5, 9 − 5 = 4, 6 − 2 = 4. Check by adding back: 4,455 + 2,548 = 7,003.
- 3.945. Break 35 into 30 and 5: 27 × 30 = 810 and 27 × 5 = 135; 810 + 135 = 945. Breaking the 27 instead works just as well: 20 × 35 = 700 and 7 × 35 = 245; 700 + 245 = 945.
- 4.17. Parentheses first: 9 − 3 = 6. Then multiplying and dividing, left to right: 2 × 6 = 12, and 12 ÷ 4 = 3. Subtracting last: 20 − 3 = 17. Working straight across from the left instead (20 − 2 = 18, and so on) gives a different number, and that is the trap the question sets.
- 5.7. Start at −8 and go up 15. The first 8 steps bring you to 0; the other 7 take you to 7. Another way to see it: the 15 and the 8 pull in opposite directions, so find the difference, 15 − 8 = 7, and the answer takes the sign of the larger, which is positive.
- 6.12. Subtracting a negative is the same as adding a positive: 3 − (−9) = 3 + 9 = 12. On a number line, taking away 9 below zero moves you 9 up.
- 7.42. Two negatives multiplied give a positive: 7 × 6 = 42, and the two minus signs cancel each other. One negative and one positive would give a negative.
- 8.1720. Fifths and quarters do not match. Twentieths hold both: 35 = 1220 and 14 = 520. Then 12 + 5 = 17 twentieths. Nothing divides both 17 and 20, so it is already in simplest form.
- 9.14. Multiply straight across: 2 × 3 = 6 on top, 3 × 8 = 24 underneath. 624 reduces to 14. You can also cancel first: the 3 on top and the 3 underneath divide out, leaving 28, which is 14.
- 10.6. The question is how many eighths fit inside three quarters. Three quarters is six eighths, so the answer is 6. The rule says the same thing: turn the second fraction over and multiply, 34 × 81 = 244 = 6.
- 11.710. In thirtieths, 23 = 2030 and 710 = 2130. Twenty-one parts beat twenty, so 710 is larger, by one thirtieth. As decimals: 23 is 0.666…, and 710 is 0.7.
- 12.4.55. Line up the decimal points and write 9.2 as 9.20 so the places match: 9.20 − 4.65 = 4.55. Check: 4.55 + 4.65 = 9.20.
- 13.0.36. Multiply as whole numbers: 8 × 45 = 360. Then count the decimal places in the question — one and two, three in all — and put three into the answer: 0.360, which is 0.36. It makes sense that the answer is smaller than 0.45: you took less than one whole of it.
- 14.0.625. A fraction is a division: 5 ÷ 8. Eight does not go into 5, so 5.000 ÷ 8 = 0.625. Or build it from a fact worth knowing: 18 = 0.125, and five of those is 0.625.
- 15.$285.00. 12 × 23.75: 12 × 23 = 276 and 12 × 0.75 = 9, because three quarters of 12 is 9; 276 + 9 = 285.
- 16.28. 10% of 80 is 8, so 30% is three of those, 24. 5% is half of 8, which is 4. Together: 24 + 4 = 28. Another way: 35% is 0.35, and 0.35 × 80 = 28.
- 17.$42. 10% of 60 is 6, so 30% is 18. Take it off: 60 − 18 = 42. Or notice that paying 30% less means paying 70%, and 70% of 60 is 42.
- 18.30%. Percent means per hundred. 1240 reduces to 310, and three tenths is 30 per hundred. Another way: 40 goes into 100 two and a half times, so 12 × 2.5 = 30.
- 19.325 miles. One gallon takes the car 130 ÷ 4 = 32.5 miles, so 10 gallons take it 10 × 32.5 = 325 miles. Set up as a proportion it reads 4/130 = 10/x; cross-multiplying gives 4x = 1,300, so x = 325.
- 20.96. A pound is 16 ounces: 6 × 16 = 96. (6 × 10 = 60 and 6 × 6 = 36; 60 + 36 = 96.)
- 21.20. A gallon is 4 quarts: 5 × 4 = 20. Going from a larger unit to a smaller one means more of them, so multiply.
- 22.40. Three feet is 3 × 12 = 36 inches. Add the 4: 36 + 4 = 40.
- 23.42 square inches. Area of a triangle is half of base × height: 12 × 7 = 84, and half of 84 is 42. A triangle is half of the rectangle that would just hold it, which is where the half comes from.
- 24.78.5 square cm. Area of a circle is π × r²: 5 × 5 = 25, and 3.14 × 25 = 78.5. The formula is on the sheet; choosing it, and squaring the radius before multiplying by π, is the work.
- 25.13. Pythagorean theorem: a² + b² = c². 5² + 12² = 25 + 144 = 169, and √169 = 13. The hypotenuse is the longest side, and 13 is longer than both legs, as it should be.
- 26.48°. When two lines cross, the angles opposite each other are equal. Each pair of neighbors adds to 180°: the angle next to the 48° is 132°, and the angle opposite is 180° − 132° = 48° again, which is what makes it so.
- 27.160 cubic inches. Volume of a box is length × width × height: 8 × 5 = 40, and 40 × 4 = 160.
- 28.125.6 cubic inches. Volume of a cylinder is π × r² × h: 2 × 2 = 4, 4 × 10 = 40, and 3.14 × 40 = 125.6. In words: the circle on the bottom has an area of 12.56 square inches, and the can stacks ten of those.
- 29.26. Read the two rows: Thursday 71, Tuesday 45. Subtract: 71 − 45 = 26.
- 30.12. Add them: 15 + 9 + 13 + 11 = 48. Divide by how many there are: 48 ÷ 4 = 12.
- 31.9. Put them in order first: 3, 6, 9, 10, 14. The median is the middle one: 9, with two numbers below it and two above.
- 32.19. The range is the largest minus the smallest: 27 − 8 = 19.
- 33.13. Probability is the favorable outcomes over all the outcomes. There are 4 black pens out of 2 + 6 + 4 = 12 pens: 412, which reduces to 13.
- 34.55%. Either it snows or it does not, and the two chances together make one whole, which is 100%: 100 − 45 = 55.
- 35.20. Each of the 5 bowls can go with any of the 4 drinks: 5 × 4 = 20. Counting a choice made in two steps means multiplying the steps.
- 36.125. 5³ means 5 × 5 × 5. 5 × 5 = 25, and 25 × 5 = 125. It is not 5 × 3.
- 37.12. The square root of 144 is the number that, multiplied by itself, gives 144: 12 × 12 = 144.
- 38.x9. Same base, so keep the base and add the exponents: 4 + 5 = 9. Four factors of x times five more makes nine factors of x.
- 39.1. Any number except 0 raised to the power 0 is 1. One way to see it: 12² ÷ 12² = 1, and the subtract-the-exponents rule says that same division is 120.
- 40.4.5 × 107. Move the decimal point until one digit stands before it: 4.5. It moved 7 places, so the power of ten is 7. Check: 4.5 × 10,000,000 = 45,000,000.
- 41.9x + 5. Gather like with like. The x terms: 7x + 2x = 9x. The plain numbers: −4 + 9 = 5.
- 42.15x − 10. Multiply each term inside by 5: 5 × 3x = 15x, and 5 × (−2) = −10.
- 43.x² − 3x − 10. Multiply every term in the first binomial by every term in the second: x × x = x², x × (−5) = −5x, 2 × x = 2x, and 2 × (−5) = −10. Gather the x terms: −5x + 2x = −3x.
- 44.x = 7. Undo the addition first: take 5 from both sides, 4x = 28. Then undo the multiplication: divide both sides by 4, x = 7. Check: 4 × 7 + 5 = 33.
- 45.x = 8. Gather the x terms on one side: take 5x from both sides, 3x − 9 = 15. Add 9 to both sides: 3x = 24. Divide by 3: x = 8. Check: 8 × 8 − 9 = 55, and 5 × 8 + 15 = 55.
- 46.x < 5. Solve it as you would an equation: take 4 from both sides, 3x < 15, then divide both sides by 3, x < 5. The sign stays as it is, because you divided by a positive number. Any number below 5 works: try 4, and 3 × 4 + 4 = 16, which is less than 19.
- 47.6 hours. Let h be the hours: 75 + 40h = 315. Take 75 from both sides: 40h = 240. Divide by 40: h = 6. Check: 75 + 40 × 6 = 75 + 240 = 315.
- 48.3. Slope is rise over run. Rise: 14 − 2 = 12. Run: 5 − 1 = 4. Slope = 12 ÷ 4 = 3. The line climbs 3 for every 1 it moves to the right.
- 49.Slope 2, y-intercept −7. In y = mx + b, the number multiplying x is the slope and the number added is the y-intercept, where the line crosses the y-axis. Here the added number is −7, so the line crosses the y-axis below zero, at (0, −7).
- 50.3. Read the marked points: (1, 2) and (2, 5). Rise: 5 − 2 = 3. Run: 2 − 1 = 1. Slope = 3 ÷ 1 = 3.
- 51.x = 9, y = 6. Add the two equations and the y terms cancel: 2x = 18, so x = 9. Put x back into the first: 9 + y = 15, so y = 6. Check the second: 9 − 6 = 3.
- 52.22. f(6) means put 6 in place of x: 3 × 6 + 4 = 18 + 4 = 22.
- 53.x = 7. Set the rule equal to 27 and solve: 5x − 8 = 27, so 5x = 35 and x = 7. Check: 5 × 7 − 8 = 27.
- 54.(5, 2). Start at 0. Go 5 to the right, then 2 up. The first number is the distance across, the second is the distance up. Written the other way around, (2, 5) names a different point.
- 55.(−1, 3). The midpoint averages the x values and averages the y values: (−4 + 2) ÷ 2 = −2 ÷ 2 = −1, and (1 + 5) ÷ 2 = 3. A negative and a positive average the same way as any two numbers: add them, then halve. The picture agrees: the circled point sits one step left of the y-axis and three steps up.