Pictogram (II): One symbol = many
FoundationOne symbol can stand for 2, 5, 10 items.
After this lesson, you can:
- Always read the key first.
- Symbols x key = real amount.
- Half a symbol = half the key value.
Before this lesson you should know: HK Money (II): $10–$100
1Summary 重點摘要
One symbol can stand for 2, 5, 10 items.
2Vocabulary cards Vocabulary
S
Symbol圖案
The picture used in the chart.
K
Key圖例
Says what one symbol stands for.
S
Stand for代表
To mean a certain amount.
M
Multiply乘
Pictures x key value.
H
Half symbol半個圖案
Half the key value.
M
Most popular最受歡迎
The item with the biggest count.
C
Compare比較
Which row has more or fewer.
F
Frequency次數
The real count.
3Step by step Steps
- Step 1: Read the keyWhen reading a pictogram, read the key first: it explains how much one symbol stands for. If one sun stands for 4 hours, remember that number first, because every later calculation uses it. Counting symbols without the key easily leads to wrong answers.
- Step 2: Count symbolsAfter the key, count the symbols in each row. For example, Monday's row has 3 suns. Count row by row slowly, pointing with a pencil tip, so nothing is missed or counted twice. Getting the number of symbols right is what makes the calculation correct.
- Step 3: MultiplyWhen one symbol stands for many, use multiplication: Monday has 3 suns, and 3 × 4 = 12, so Monday has 12 hours of sunshine. The number of symbols times the value of one symbol gives the real amount.
- Step 4: Half symbolsSometimes half a symbol appears: half a sun stands for half of 4, which is 2 hours. Work out the whole symbols first, then add the half. For example, two whole suns and a half give 4 + 4 + 2 = 10 hours.
- Step 5: CompareTo compare two days of sunshine, work out the real amounts first: Monday 12 hours, Tuesday 16 hours. Since 16 > 12, Tuesday has more sunshine. Compare the calculated numbers, not the symbols directly.
- Step 6: Answer the questionFinally read carefully what the question asks: for the total of two days, add the two amounts, 12 + 16 = 28 hours; for which day has more, compare the sizes. Choosing the right method for the question keeps the answer on target.
4Diagrams Diagrams
5Worked example Example
Example: the key of a pictogram says one apple symbol stands for 5 people. The apple row has 4 symbols. How many people chose apples?
- Read the key first: 1 apple symbol stands for 5 people; this is the key number for the calculation.
- Then count the symbols: the apple row has 4 symbols, counted one by one.
- Multiply: 4 × 5 = 20; four symbols times 5 people each.
- Check and answer: 20 people chose apples; 5 + 5 + 5 + 5 = 20 gives the same result.
- Answer: 20 people chose apples. The key says 1 symbol stands for 5 people and the row has 4 symbols, so 4 × 5 = 20; adding back, 5 + 5 + 5 + 5 = 20 gives the same result, so the answer is correct.
6Common mistakes Mistakes
✗ Ignoring the key
✓ One symbol may mean 2, 5 or 10; read the key first
✗ Adding instead of multiplying
✓ 4 symbols x 5 = 20; not 4 + 5
✗ Counting half a symbol as one
✓ Half = half the key value, e.g. half sun = 2 hours
✗ Comparing symbol counts
✓ Compare the real totals after multiplying, not the symbols
7Quick check Quick check
Q11 symbol = 5 people; 3 symbols?
Answer: 15
Did you get it right?
Q2Where is the key shown?
Answer: Near the title
Did you get it right?
Q31 sun = 4 hours; 2 and a half suns?
Answer: 10 hours
Did you get it right?
Q4What represents amounts?
Answer: Symbols
Did you get it right?
Q55 symbols, 1 = 10. Total?
Answer: 50
Did you get it right?
8Recap Recap
- Always read the key first.
- Symbols x key = real amount.
- Half a symbol = half the key value.
- Compare the totals after multiplying.
- Add rows to get the grand total.