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Virginia Standard Breakdown
Virginia Standard Breakdown
Students will learn how to estimate, solve, and explain problems using addition, subtraction, multiplication, and division with decimals. They’ll work with both single-step and multi-step problems.
Students will be able to
Make a good estimate before solving to check if their answer makes sense.
Add, subtract, multiply, and divide decimals.
Solve word problems that use decimals (like money or measurements).
Explain how they solved the problem and why their answer is reasonable.
When Will I ever use this?
When Will I ever use this?
💵 Money & Shopping
Add up prices when you’re buying snacks or clothes.
Estimate the total before you get to the checkout.
Figure out how much change you should get.
🍪 Cooking & Baking
Measure ingredients like 0.5 cups of sugar.
Double or cut recipes in half.
📏 Measuring Stuff
Use a ruler or tape measure (like 3.75 inches).
Track your height - Can you ride the roller coaster at Kings DOminion
Read numbers on science experiments.
🏀 Sports & Fitness
Time your laps (like 5.25 minutes).
Keep up with batting averages or shooting percentages.
Measure how far you throw or run.
🎮 Everyday Life & Fun
Estimate how long your phone battery will last (35.5%).
Split a pizza bill with friends or family.
Rounding Decimals to the nearest whole number
Rounding Decimals to the nearest whole number
Find the whole-number part (the number left of the decimal).
Look at the tenths digit (the first digit after the decimal).
Decide:
Tenths 0–4 → round down (whole number stays).
Tenths 5–9 → round up (add 1 to the whole number).
Write the rounded answer (no decimal needed).
Example : 3.2 → tenths = 2 → round down → 3 8.76 → tenths = 7 → round up → 9
Adding Decimals
Adding Decimals
Line up the decimal points — write the numbers vertically so the decimal points are one under the other.
Add zeros so both numbers have the same number of digits after the decimal (e.g., 1.4 → 1.40).
Add from right to left, just like whole numbers. Add hundredths, then tenths, then the ones — carry when needed.
Put the decimal point in the answer directly under the other decimal points.
Check with estimation (round each number and add) to see if your answer is reasonable.
Subtracting Decimals
Subtracting Decimals
Line up the decimal points. Write the numbers vertically with the decimals one under the other.
Add zeros so both numbers have the same number of digits after the decimal (e.g., 4.8 → 4.80).
Subtract right to left (start with the smallest place value).
Borrow if needed: if a digit is too small to subtract from, borrow from the next column to the left — this may mean borrowing from the ones place into the tenths, then from tenths into hundredths, etc.
Place the decimal point in the answer directly under the other decimal points.
Check your work by adding the answer to the number you subtracted (the subtrahend). The sum should equal the original first number (the minuend).
Multiplying Decimals
Multiplying Decimals
Ignore the decimals for now – Pretend the numbers are whole numbers.
Multiply the numbers as if they are whole numbers.
Count the decimal places in the numbers you are multiplying.
Add the decimal places together to find how many decimals go in your answer.
Place the decimal in your answer so it has that many decimal places.
Check your answer – Does it make sense?
** You can use the lattice method for this just like reglar multiplying to place the decimal just count the number of digits behind the two original decimals and move the decimal in your answer just like in the traditional algorithm from left to right.
Dividing Decials
Dividing Decials
Check the divisor (the number you are dividing by).
If it’s a decimal, move the decimal to the right until it becomes a whole number.
Move the decimal in the dividend (the number being divided) the same number of places as you moved the divisor.
Divide as usual using long division.
Place the decimal in the quotient (answer) directly above its place in the dividend.
Add zeros if needed to continue dividing after the decimal.
Check your answer by estimating or multiplying.
** You can use the box method for dividing decimals as well just bring up the decimal**
Dividing DecimalS - Box Method
Dividing DecimalS - Box Method
Multiplying Decimals - Lattice Method
Multiplying Decimals - Lattice Method
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