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Grade 4 Math Study Guide

Alpha School · Math · built 2 October 2026

This guide covers the nine kinds of questions a grade 4 math test asks, one section each. Every section starts with something you can already do, adds one new move, gives you the rule in a sentence, and names the trap to watch for. Then you practice.

Every question here is new. None of them is from a test. The numbers and stories are different on purpose, because the skill is what carries over, not the numbers.

How to use it: answer, press Check, then read the answer even when you were right. The answer tells you where each wrong choice comes from, and that is how you learn to spot the trap next time. Between sections there are mixed checks that do not tell you which skill to use. The mixed run at the end is like the test: no labels at all.

In this guide

1. Place value and rounding

Start here

What is the value of the 7 in 4,702?

4,702 is 4 thousands, 7 hundreds, 0 tens and 2 ones.

The 7 sits in the hundreds place, so its value is 700. Not 7. The digit is 7; the value is 700.

The new part

Now the same idea used two ways.

Clue puzzles. "The value of the 3 is 30,000. The value of the 8 is 800. The value of the 5 is 5." Put each digit where its value says: 3 in the ten-thousands, 8 in the hundreds, 5 in the ones. That gives 3_,8_5. Any number with that shape fits, such as 32,815.

Rounding. Round 8,462 to the nearest hundred. Underline the hundreds digit: 8,462. Look at the one digit to its right, the 6. It is 5 or more, so the 4 goes up to 5 and everything after it becomes zero.

8,462 rounded to the nearest hundred is 8,500.

Check: 8,462 sits between 8,400 and 8,500, and it is closer to 8,500.

The rule

A digit's value is the digit times its place.

To round: underline the place, look at the one digit to its right. 5 or more, round up. Less than 5, keep the digit and zero the rest.

Watch out for

Rounding to the wrong place. Asked for the nearest hundred, it is tempting to look at the ones digit and round to the nearest ten instead, giving 8,460. Underline the place the question names before you look anywhere else.

Digit instead of value. "The value of the 7" is 700, never 7. If the clue says the value of a digit is 40,000, that digit is in the ten-thousands place.

Practice

  1. What is the value of the digit 6 in 56,318?

    Value
  2. A number is described by these clues.

    • The value of the 8 is 80,000.
    • The value of the 2 is 200.
    • The value of the 5 is 5.

    Which number fits all three clues?

    Number
  3. Round 6,249 to the nearest hundred.

    Rounded number
  4. A stadium sold 35,972 tickets. What is 35,972 rounded to the nearest thousand?

    Rounded number

2. Decimals and fractions

Start here

A bar is cut into 10 equal parts and 3 of them are shaded. What fraction of the bar is shaded?

10 equal parts, 3 shaded: 3/10, three tenths.

The new part

Three tenths has a second name. The first place after the decimal point is the tenths place, so three tenths is written 0.3.

Cut each tenth into 10 smaller pieces and the bar has 100 pieces. Each piece is one hundredth. The hundredths place is the second place after the point.

3/10 = 0.3.

30/100 = 0.30.

0.3 and 0.30 name the same amount, because 3 tenths is 30 hundredths.

7/100 = 0.07. Only 7 hundredths, so the tenths place holds a 0.

On a number line from 0 to 1 cut into ten equal jumps, each jump is one tenth. The sixth mark after 0 is 0.6.

The rule

Tenths are the first place after the decimal point; hundredths are the second.

A fraction with 10 on the bottom fills one place. A fraction with 100 on the bottom fills two places.

Watch out for

Putting the digits straight after the point. 45/100 looks like it should be 0.045 or 4.5, but 100 on the bottom means exactly two places: 0.45.

Reading 0.07 as seven tenths. The 7 is in the second place, so it is seven hundredths. The 0 in the tenths place is doing a job: it says there are no tenths.

Practice

  1. The large square is divided into 100 equal parts. What fraction of the square is shaded?

    Fraction
  2. Which decimal names the same amount as 6/100?

    Decimal
  3. Point P is on the number line. Which decimal does point P represent?

    00.51P
    Decimal
  4. Dev ran 0.85 of a mile before school. Which fraction is equivalent to 0.85?

    Fraction

Mixed check 1

Mixed check 1

These two questions do not say which skill they use. Decide the method first, then answer.

  1. Round 7,350 to the nearest thousand.

    Which method does this need?
    Rounded number
  2. A bar is divided into 10 equal parts and 9 of them are shaded. Which decimal shows the shaded part?

    Which method does this need?
    Decimal

3. Multiply big numbers

Start here

What is 6 × 40?

6 × 4 tens is 24 tens.

24 tens is 240.

So 6 × 40 = 240. A fact you know, with a zero carried along.

The new part

Bigger numbers are the same move, done for every piece. Break each number into its places, multiply every piece by every piece, then add.

23 × 14. Break 23 into 20 + 3 and 14 into 10 + 4.

20 × 10 = 200.

20 × 4 = 80.

3 × 10 = 30.

3 × 4 = 12.

200 + 80 + 30 + 12 = 322.

Three digits times one digit works the same way. 348 × 6:

300 × 6 = 1,800.

40 × 6 = 240.

8 × 6 = 48.

1,800 + 240 + 48 = 2,088.

The rule

Break each number into its places. Multiply every part by every part. Add all the pieces.

Watch out for

Fronts and backs only. 23 × 14 is not 20 × 10 plus 3 × 4. That misses 20 × 4 and 3 × 10 and gives 212, which will be one of the choices. Four pieces for two-digit times two-digit, every time.

"Not here". When a choice list ends with "Not here", work the problem first, then look for your answer. If it is missing, and your check by estimating agrees with you, "Not here" is the answer.

Practice

  1. What is 7 × 300?

    Product
  2. Which expression shows 36 × 24 broken into parts that can be multiplied one at a time?

    Expression
  3. What is 418 × 7?

    Product
  4. A theater has 28 rows of seats. Each row has 32 seats. How many seats are in the theater?

    Seats

4. Divide with remainders

Start here

What is 72 ÷ 8?

Think: 8 times what makes 72? 8 × 9 = 72.

So 72 ÷ 8 = 9.

The new part

Divide a bigger number place by place. 653 ÷ 4:

600 ÷ 4 = 150.

53 ÷ 4 is 13 with 1 left over, because 4 × 13 = 52.

150 + 13 = 163, remainder 1.

Check by multiplying back: 4 × 163 = 652, and 652 + 1 = 653.

Now the part that is really the skill: deciding what the remainder means. 653 pencils, 4 in each box.

The rule

Divide place by place, keep the remainder smaller than the divisor, and check by multiplying back.

Then read the question again and decide what the remainder means: drop it, round up, or report it.

Watch out for

Dropping the remainder when something still needs a place. Vans, boxes, tables and shelves all round up: one more is needed for the leftovers.

Reporting a remainder bigger than the divisor. 53 ÷ 4 is not 12 remainder 5. If the remainder is 4 or more you can divide once more.

Practice

  1. What is 56 ÷ 7?

    Quotient
  2. A baker has 275 muffins and packs 6 muffins in each box. Which expression can be used to find how many full boxes the baker packs?

    Expression
  3. A library puts 936 books onto 4 shelves with the same number of books on each shelf. How many books go on each shelf?

    Books per shelf
  4. A school van holds 9 students. 203 students are going on a trip. How many vans are needed so that every student has a seat?

    Vans

Mixed check 2

Mixed check 2

These two questions do not say which skill they use. Decide the method first, then answer.

  1. A rope 437 feet long is cut into pieces that are each 5 feet long. How many whole pieces can be cut?

    Which method does this need?
    Whole pieces
  2. What is 32 × 15?

    Which method does this need?
    Product

5. Multi-step equations

Start here

Naomi had $40 and spent $12. How much does she have left?

40 minus 12 equals 28. She has $28 left.

The whole was $40; one part is $12; the other part is $28.

The new part

Longer problems are the same whole-and-parts idea, used more than once.

Profit. Lin's supplies for a lemonade stand cost $18. She took in $65. Profit is what she took in minus what she spent: 65 minus 18 equals 47.

Change. Pay with a $50 bill for three things: add the three things first, then subtract that total from 50.

Writing the equation. Over three years a club collected 1,245 cans. Year one: 418. Year two: 506. Which equation finds n, the cans in year three? The parts add to the whole:

418 + 506 + n = 1,245.

A strip diagram shows the same thing: 1,245 across the top, and 418, 506 and n side by side underneath.

The rule

Find the whole and the parts first. The parts add up to the whole, so a missing part is the whole minus the known parts.

Watch out for

Right numbers, wrong operation. 1,245 + 418 + 506 = n uses all the right numbers and adds the whole to its own parts. Ask: is n a part or the whole?

Subtracting only one thing from the bill. If three items were bought, all three come off the $50, not just the first one.

Practice

  1. A book costs $9 and a pen costs $4. What is the total cost?

    Total
  2. Over three weeks Raul read 1,120 pages. He read 365 pages in week one and 410 pages in week two. Which equation can be used to find p, the number of pages Raul read in week three?

    Equation
  3. Priya spent $37 on supplies for a craft stall. She sold her crafts for a total of $112. What was Priya's profit?

    Profit
  4. Ken pays with a $50 bill. He buys one game for $18, two posters for $6 each, and a snack for $3. How much change should Ken receive?

    Change

6. Fraction add and compare

Start here

A pizza is cut into 8 equal slices and you eat 3. What fraction of the pizza did you eat?

3/8. Three of the eight equal slices.

The bottom number names the size of the slice. The top number counts slices.

The new part

Adding and subtracting with the same denominator is counting slices. 3 slices and 2 more slices is 5 slices, all eighths:

3/8 + 2/8 = 5/8.

The denominator does not change. You are still counting eighths.

Two friends finished 7/10 of a mural together. One of them did 4/10. The other did 7/10 − 4/10 = 3/10.

Comparing. Same denominator: more slices is more. Same numerator: the bigger denominator means smaller slices, so 5/8 is less than 5/6. Different everything: compare each to one half. 3/10 is less than a half; 2/3 is more than a half.

More than one whole. If five friends each drink one fourth of a jug, that is 5/4 of a jug, which is one whole jug and one more fourth.

The rule

Same-size pieces: add or subtract the counts and keep the piece name.

To compare, make the pieces alike, or compare each fraction to one half.

Watch out for

Adding the denominators. 3/8 + 2/8 is not 5/16. Sixteenths never appeared; you only had eighths. The answer 5/16 is smaller than 3/8 on its own, which cannot be right for a sum.

Bigger denominator, bigger fraction. 1/6 looks bigger than 1/4 because 6 is bigger than 4. But cutting into 6 pieces makes each piece smaller.

Practice

  1. What is 3/8 + 2/8?

    Sum
  2. Together, Ana and Beto painted 9/12 of a fence on Saturday. Ana painted 5/12 of the fence. Which expression can be used to find the fraction of the fence Beto painted?

    Expression
  3. Which comparison is true?

    Comparison
  4. Five friends each drank one fourth of a jug of lemonade. The picture shows the two jugs with the parts they drank shaded. Which fraction shows how many jugs of lemonade the friends drank?

    Jug 1Jug 2
    Fraction

Mixed check 3

Mixed check 3

These two questions do not say which skill they use. Decide the method first, then answer.

  1. Which fraction is greater, 2/5 or 2/3?

    Which method does this need?
    Greater fraction
  2. Jo had $60. She bought a shirt for $24 and socks for $7. How much money does Jo have left?

    Which method does this need?
    Money left

7. Angles and shapes

Start here

How many degrees are in a right angle? In a straight angle?

A right angle, the corner of a square, is 90°. A straight angle, a flat line, is 180°.

Smaller than 90° is acute. Between 90° and 180° is obtuse.

The new part

Reading a protractor. A protractor has two rows of numbers. Put the center on the vertex and one ray along the zero line. Read the row of numbers that starts at 0 on that ray. If you only have the other row, the two rows always add to 180, so subtract from 180.

The ray crosses 40 on the row that does not start at 0 on your zero ray.

180 minus 40 equals 140, so the angle is 140°.

Check with your eyes: the angle opens past a right angle, so it must be more than 90°. 140° fits; 40° does not.

Naming triangles. Name a triangle by its biggest angle. One right angle: right triangle. One obtuse angle: obtuse triangle. All three acute: acute triangle.

Sides. Perpendicular sides meet at a right angle. Parallel sides never meet, like the long sides of a rectangle.

Symmetry. A line of symmetry is a fold that matches the two halves exactly. Check the vertical fold and the horizontal fold separately.

The rule

Read the protractor from the row that starts at 0 on your ray, then check: wider than a right angle means more than 90°.

A triangle takes its name from its biggest angle.

Watch out for

The wrong row. Reading 40 when the angle is 140. The eye check catches it every time: obtuse means more than 90.

"Acute, because it has two acute angles." Every triangle has at least two acute angles, so that reason proves nothing. Look at the biggest angle.

Practice

  1. An angle opens wider than a right angle but less than a straight angle. Which word describes it?

    Angle type
  2. An angle is shown on the protractor. Which statement gives the measure of the angle?

    18001503012060909060120301500180
    Statement
  3. A triangle has angles that measure 90°, 35° and 55°. Which term describes this triangle?

    Term
  4. Four figures are shown. Which figures appear to have both a horizontal line of symmetry and a vertical line of symmetry?

    Figure 1Figure 2Figure 3Figure 4
    Figures

8. Perimeter and area

Start here

A rectangle is 5 cm long and 3 cm wide. Add up all four sides.

5 + 3 + 5 + 3 = 16.

The distance around the rectangle is 16 cm. That is its perimeter.

The new part

Two sides are 5 and two are 3, so the perimeter is also 2 × (5 + 3). For a square all four sides match, so perimeter is 4 × side.

Area is a different question: how many unit squares fit inside. For a rectangle, length × width.

Perimeter of the 5 by 3 rectangle: 2 × (5 + 3) = 16 cm.

Area of the 5 by 3 rectangle: 5 × 3 = 15 square cm.

The unit tells you which one you found. Centimeters for around. Square centimeters for inside.

Measurement sense. A kilogram is about the mass of a thick book or a pair of shoes; a paper clip is about a gram. Fluid ounces measure liquid: a 60 fl oz jug fills seven 8 fl oz glasses with 4 fl oz left, because 60 ÷ 8 is 7 remainder 4.

The rule

Perimeter is the distance around: add the sides. Area is the squares inside: multiply length by width.

Check the unit. Plain units for around, square units for inside.

Watch out for

Answering the other one. The question says perimeter and the hand multiplies. Say the word "around" or "inside" to yourself before you write anything.

Squares. Side × side is area. Perimeter of a square is side × 4.

Practice

  1. A square playground has sides that are each 9 yards long. What is the perimeter of the playground in yards?

    Perimeter
  2. A rectangular garden is 14 meters long and 6 meters wide. Which expression gives the area of the garden in square meters?

    Expression
  3. A small watermelon has a mass of about 2 kilograms. Which object has a mass closest to 2 kilograms?

    Object
  4. A spool holds 75 feet of ribbon. Mira cuts 8-foot pieces until there is not enough ribbon left to cut another whole piece. How many feet of ribbon are left on the spool?

    Left on the spool

Mixed check 4

Mixed check 4

These two questions do not say which skill they use. Decide the method first, then answer.

  1. A triangle has angles that measure 120°, 30° and 30°. Which term describes the triangle?

    Which method does this need?
    Term
  2. A rectangular pen is 12 feet long and 7 feet wide. How many feet of fencing are needed to go all the way around the pen?

    Which method does this need?
    Fencing

9. Data and patterns

Start here

In a stem-and-leaf plot, what number does the row "3 | 7" stand for?

The stem is the tens digit and the leaf is the ones digit. 3 | 7 is 37.

A row "2 | 0 3 3 7" holds four numbers: 20, 23, 23 and 27.

The new part

Greatest minus least. The least value is the first leaf of the first stem. The greatest is the last leaf of the last stem. Subtract.

Dot plots. One dot for each item, placed above its value. A table saying "4 meters: 3 boats" becomes 3 dots stacked above the 4.

Rule tables. A rule like "multiply the position by 3, then add 1" gives position 1 → 4, position 2 → 7, position 3 → 10. To check a rule against a table, test every row, not only the first one.

Position 1: 1 × 3 = 3, then 3 + 1 = 4.

Position 2: 2 × 3 = 6, then 6 + 1 = 7.

Position 3: 3 × 3 = 9, then 9 + 1 = 10.

The rule

Stem is the tens, each leaf is a one. In a dot plot, count the dots above each value.

A rule is only right if it works for every row of the table.

Watch out for

Reading the leaf alone. In "3 | 7" the number is 37, not 7. In "2 | 0" the number is 20.

A rule that fits the first row only. Many rules give the right first value. Wrong choices are built to pass row one and fail row two.

Practice

  1. The stem-and-leaf plot shows the number of minutes nine students spent reading. What is the least number of minutes? What is the greatest?

    Minutes spent reading
    StemLeaf
    12 5 8
    20 3 3 7
    31 4

    Key: 2 | 5 means 25

    Least
    Greatest
  2. Using the same stem-and-leaf plot, what is the difference between the greatest and least number of minutes?

    Difference
  3. The table shows how far some toy boats floated. If these data are shown in a dot plot, how many dots will be above 4? How many above 3?

    Distance (meters)Number of boats
    23
    31
    44
    52
    Dots above 4
    Dots above 3
  4. The table shows the position of a number in a pattern and its value. Which rule describes the relationship?

    PositionValue
    12
    26
    310
    414
    Rule

Mixed run

Mixed run

Every skill in this guide, in no order, and nothing tells you which one to use. Name the method on your paper before you work it. That is exactly what the test asks.

  1. A rectangular rug is 8 feet long and 5 feet wide. What is the area of the rug in square feet? What is the perimeter of the rug in feet?

    Area (square feet)
    Perimeter (feet)
  2. Which list shows these numbers in order from least to greatest?

    40,312   43,021   40,231   34,999

    Order
  3. Which decimal is equivalent to 70/100?

    Decimal
  4. A florist makes 46 bouquets. Each bouquet uses 19 flowers. How many flowers does the florist use?

    Flowers
  5. A school receives 1,256 pencils to share equally among 7 classrooms. How many pencils does each classroom get? How many pencils are left over?

    Each classroom
    Left over
  6. Marco had $75. He bought two concert tickets for $19 each and paid $8 for parking. Which equation can be used to find m, the amount of money Marco has left?

    Equation
  7. Sam says that 3/8 + 3/8 = 6/16. Is Sam right?

    Answer
  8. Four angles are shown. Which angle does NOT appear to measure 90°?

    Angle 1Angle 2Angle 3Angle 4
    Angle
  9. The stem-and-leaf plot shows the points scored by a team in six games. What is the difference between the greatest and least number of points?

    Points scored
    StemLeaf
    51 4
    60 2 7
    73

    Key: 2 | 5 means 25

    Difference

The day before

Read this once, cold. The first move of each skill, then a few habits.

SkillFirst move
Place value and roundingSay the place the question names, underline that digit, then look one digit to its right.
Decimals and fractionsCount the places after the point: tenths is one place, hundredths is two.
Multiply big numbersBreak both numbers into their places. Every part meets every part.
Divide with remaindersDivide place by place, check by multiplying back, then decide what the remainder means.
Multi-step equationsName the whole and the parts. A missing part is the whole minus the known parts.
Fraction add and compareSame-size pieces: count the pieces, keep the name. Comparing: make pieces alike or compare to one half.
Angles and shapesRead the protractor row that starts at 0 on your ray, then check: obtuse means more than 90.
Perimeter and areaSay "around" or "inside" first. Around adds the sides; inside multiplies them.
Data and patternsStem is tens, leaf is ones. Test a rule on every row of the table.

Habits