Da VIP Academy / GED / Math / Number Sense & Operations
Whole Number Operations
Add, subtract, multiply, and divide whole numbers, including multi-step word problems.
How it works
Line up place value
When you add or subtract, stack the numbers so ones sit under ones and tens under tens. Carry when a column passes 9; borrow when the top digit is too small.
Decide the operation from the story
Words like total, combined, and altogether mean add. Left, fewer, and difference mean subtract. Each, per, and groups of mean multiply or divide. Multi-step problems usually need two of these in order.
Worked examples
A van makes 14 trips carrying 27 boxes each. 138 boxes are returned. How many boxes were delivered?
- 14 × 27 = 378 boxes carried.
- 378 − 138 = 240 boxes delivered.
- Answer: 240.
Words to know
- Sum
- The result of adding.
- Quotient
- The result of dividing.
Test-day tips
- • Estimate first: 14 × 27 is about 14 × 30 = 420, so 378 is reasonable.
- • Reread the last sentence of a word problem before you pick an answer — it tells you what to solve for.