Theory
How do you work back to 1?
When working back to 1, you find the value of one piece, one pack, or one unit.
Divide the total value by the amount that belongs to it.
If a different amount is asked for after that, multiply the value of 1 by that amount.
- Calculate 1 firstDivide the total value by the amount to find the value of 1.
Dividing means sharing an amount fairly or seeing how many equal groups fit into it.
The first number is the total amount. The second number tells you what you divide by.
Always check whether the division works out exactly. If it does not, you get a decimal number or fraction as the answer.
- Calculate to the requested amountMultiply the value of 1 by the requested amount.
You use multiplication with equal groups.
A × B means that you take the same amount B, A times.Instead of adding again and again, you calculate the product all at once.
5 packs cost 12,5 euros. What does 1 pack cost?
- Calculate 1 first12,5 ÷ 5 = 2,5 per 1.