stack

Everyday

1. A stack is a neat pile of things one on top of another. tree →
2. To stack is to make such a pile. tree →
3. Stacks of something means a lot of it (informal): «stacks of homework». tree →
4. A stack is also a tall chimney. tree →

In the lessons

equal piles: things in each stack × stacks; in everyday life: stack the chairs at the end of the day, a stack of pancakes, stack the dishwasher; in maths: stacking cubes to build towers and count them; phrases: «a stack of», «stack up» (pile up, or compare)

Examples

• There are 5 stacks of 10 plates. tree →
• She stacks 24 books in 3 stacks. tree →
• Each stack has 12 boxes. tree →
• How tall is a stack of 8 cups? tree →
• Please stack your chairs before you go home. tree →
• He ate a stack of pancakes with syrup. tree →
• We stacked cubes into a tower of 10. tree →
• I have stacks of homework tonight. tree →
• How does our team stack up against theirs? tree →
• Then he hastily stepped behind the wood stack, and waited for what might happen next. tree →

Note

Equal groups: multiply or divide. Height of a stack = number of things × height of one (if they do not fit inside each other). Trap: cups that nest inside each other add less than their full height each.