After last year’s Number Egg Smash, Finn was keen to recreate this activity with trickier numbers to add. At the moment he’s really into counting in 10s and 100s, so I decided to go with that.


  • Egg shells in egg box
  • Spoon

Optional to support addition:


I wrote sums on some empty egg shells. Finn had to solve the sum in order to smash the egg.

When he saw the first sum was 10+10, he thought the sums weren’t going to be very tricky. But the difficulty increased with each egg smash, because the numbers were cumulative. The next sum always started with the answer from the previous egg smash.

The next sum was 20+20. As you can see, Finn got very into his egg smashing! He then moved on to 40+30.

Next was 70+30. You can hear him counting up three 10s under his breath.

He didn’t need to count up for 100+40. He knew the answer was 140, but after smashing the egg he found it tricky to find the next sum starting with 140.

140 + 10.

The next sum was 150+50. Finn decided to use the Base Ten Set to help him add up visually.

Finn was pretty confident working out 200+100 mentally, but was able to demonstrate his working out afterwards. He knew 300+500 quickly too.

He was able to work out 500+100, but used the Base Ten to work out 600+200.

The final sum was 800+200, Finn was able to tell me that the answer was ‘ten hundred’. I asked him to show me visually with the Base Ten. I find it helps him recognise that ‘ten hundred’ is the same as ‘one thousand’ without me needing to remind him. He is always interested that when you look at two hundred cubes from above, it looks like two hundred but it is actually two thousand.

DfES Early Learning Goals (2017)

Physical development

ELG 04 – Moving and handling:

Children handle equipment and tools effectively.


ELG 11 – Numbers:

Children count reliably with numbers from 1 to 20, place them in order and say which number is one more or one less than a given number. Using quantities and objects, they add two single-digit numbers and count on to find the answer.

DfES Outcomes for EYFS and National Curriculum (2013)

Numeracy Year 1 programme of study

Number – number and place value

  • count to and across 100, forwards and backwards, beginning with 0 or 1, or from any given number
  • count, read and write numbers to 100 in numerals; count in multiples of tens
  • identify and represent numbers using objects and pictorial representations including the number line, and use the language of: equal to, more than, less than (fewer), most, least

Number – addition and subtraction

  • read, write and interpret mathematical statements involving addition (+), subtraction (–) and equals (=) signs
  • represent and use number bonds and related subtraction facts within 20
  • add and subtract one-digit and two-digit numbers to 20, including zero
  • solve one-step problems that involve addition and subtraction, using concrete objects and pictorial representations