To get a double of a number, we add the same number to itself. For example, double of 3 is 3+3=6. The final quantity is double the initial.

Another way of doubling, is to multiply the number by 2. For example to double 3, or make it twice as big, you can calculate 3×2=6.



Doubling Numberblocks

Ioan started off by explaining his understanding of doubles, using his Numberblocks characters. His Duplo Numberblocks are a great way to compare numbers when halving and doubling, because he can check his answers visually, by measuring them against each other.

Doubling fruit

Then he moved on to doubling fruit. He started with one lemon.

Two satsumas/nectarines.

Three apples.

Four strawberries.

Five grapes.

Six blueberries.

Doubling 14

First, I asked Ioan if he spotted anything about his Numberblock 14. The first thing he noticed, was that I’d built him incorrectly! Then, he spotted that 7 was half the size of 14, so two sevens make 14.

Now Ioan knew that 14 was “double 7”, I asked him to use the blueberries to work out what “double 14” was. While he was moving the blueberries, he told me that he thought the answer would be 28, before he counted them up.

I questioned further to try and get Ioan to explain how he knew that two fourteens would be 28.

DfES Outcomes for EYFS and National Curriculum (2013)

Numeracy Year 1 programme of study

Number – addition and subtraction

  • read, write and interpret mathematical statements involving addition (+), subtraction (–) and equals (=) signs
  • add and subtract one-digit and two-digit numbers to 20, including zero

Number – multiplication and division

  • solve one-step problems involving multiplication and division, by calculating the answer using concrete objects, pictorial representations and arrays with the support of the teacher.