KA-0118Reading tables, charts, and graphs
3 points, difficulty 1 of 3Level 3–4about 45sThe chart shows how many books four children read. How many did they read altogether?
Text description of the figure
A bar chart with four bars labelled Ana, Bo, Cal and Dee. The vertical axis is marked in steps of 5 from 0 to 25. The bars reach 10, 25, 5 and 15.
Hints
Take them one at a time. The first gives nothing away.
1A nudge
Read the axis before you read the bars.
2The strategy
Work out what one gridline is worth, then read every bar in turn and write the numbers down before adding. Missing a short bar is easy when the numbers stay in your head.
3The full solution
The axis goes up in fives. The bars are 10, 25, 5 and 15, and 10 + 25 + 5 + 15 = 55.
Solution— no shortcut on this one
Read the scale first: the axis is marked in steps of 5. The four bars are then 10, 25, 5 and 15. Write them down before adding: 10 + 25 + 5 + 15 = 55. The transferable idea: read the axis, write down every value, then add - the short bar is the one that gets forgotten.
Why this is on the test: Chart questions are lost on the scale and on dropping a value, not on the arithmetic, and both traps are live here.