Alien Invaders 2.0


Posted by Perri Wilkinson | Posted in Decimals, Division, Multiplication, Place Value, Subtraction | Posted on August 28, 2017

This is a warm up activity involving calculators for place value, decimals, subtraction multiplication and division.

Students begin by entering a 4 digit number into their calculator. These 4 digits are aliens coming down to earth. The students’ mission is to shoot them down in ascending order but this can only by subtracting the ones. Students will have to change the value of each digit by either multiplying or dividing the number by 10, 100 or 1000.

For example:

  • A student starts with the number 5236.
  • The first number they have to shoot down is the 2. Therefore, they must divide their number by 100 so that the 2 is in the ones column, e.g. 52.36. Then they can subtract 2, leaving 50.36.
  • Next they must shoot down the 3. First the must multiply their number by 10 making 503.6 and then they can subtract 3, leaving 500.6
  • Students continue until all digits are gone.

Write a comment

Skip to toolbar