Example 1
A community centre has 1,245 visitors in one week and 836 the next week. How many altogether?
- The question asks for a total, so add.
- Line up the place values.
- 1,245 + 836 = 2,081
So: There are 2,081 visitors altogether.
Back to National 3
Unit: Numeracy
Number Skills
Number skills help you choose and carry out calculations in everyday situations. National 3 uses whole numbers up to 10,000, simple decimals, rounding and sensible checks.
Supports assessment standards: 1.1, 1.2, 1.4, 1.5
Topic explanation
Read the whole situation before choosing an operation. A total often needs addition, a difference or change needs subtraction, equal groups need multiplication, and equal sharing needs division.
Keep place values lined up. In decimal calculations, line up the decimal points so tenths stay with tenths and hundredths stay with hundredths.
Use rounding or estimation as a separate check. The exact answer should be close to the estimate.
Quick methods
- Add or subtract
- Line up the place values and decimal points.
- Multiply
- Use equal groups or repeated amounts.
- Divide
- Share a total equally or find how many groups fit.
- Estimate
- Round first to check whether an answer is sensible.
Worked examples
Example 2
384 items are shared equally between 6 groups. How many are in each group?
- The total is shared equally, so divide.
- 384 divided by 6 = 64
- Check: 64 × 6 = 384
So: There are 64 items in each group.
Example 3
Estimate 468 + 327 by rounding to the nearest 100.
- 468 rounds to 500.
- 327 rounds to 300.
- 500 + 300 = 800
So: The estimated total is 800.