Ever wondered how one little ball can stand for 4 goals?
At the inter-house sports, Red House's row on the notice board shows ⚽⚽⚽ and half a ⚽. Chidi says that's 3½ goals — which is impossible! The secret is the key at the bottom of the chart.
Revision notes
Read pictures and bars to find values, totals and differences — and always check the key!
At the inter-house sports, Red House's row on the notice board shows ⚽⚽⚽ and half a ⚽. Chidi says that's 3½ goals — which is impossible! The secret is the key at the bottom of the chart.
A pictogram uses small pictures to show data. The key tells you what one picture stands for.
If each ⚽ = 4 goals, then ⚽⚽⚽ stands for 3 × 4 = 12 goals.
Half a picture stands for half the key: half a ⚽ = 2 goals. So ⚽⚽⚽ and half a ⚽ = 12 + 2 = 14 goals.
🔑 Key idea: Value = number of pictures × the key.
To draw a row, divide the value by the key. With each 🍞 = 10 loaves, 35 loaves needs 35 ÷ 10 = 3.5 pictures: three whole loaves and half a loaf.
Choose a key that divides your numbers nicely, and keep every picture the same size so the rows are fair to compare.
🔑 Key idea: Number of pictures = value ÷ key.
A bar chart shows each answer as a bar. The height of the bar, read from the scale on the side, is the frequency.
The tallest bar is the most popular; the shortest is the least popular.
“How many more?” means subtract the two bar heights. “How many altogether?” means add all the bars.
🔑 Key idea: Bar height = frequency. More → subtract; altogether → add.
A pictogram shows the loaves of bread a bakery in Enugu sold each day. Key: each 🍞 = 4 loaves. The row for Thursday shows 🍞🍞🍞🍞🍞 and half a 🍞. How many loaves does the row for Thursday stand for?
Step 1: Whole symbols
5 × 4 = 20
Step 2: Half a symbol
half of 4 = 2
20 + 2 = 22
Answer: 22
Ready to check you've got it? Scroll up and work through the lesson: the interactive visuals, practice questions and mastery check are all there.