Addition and Subtraction

Lesson

We've previously seen how to subtract multiples of 10 from a two digit numbers.

Subtracting multiples of 100 form a three digit number is a similar process, but this time we have to consider three place values; The hundreds, the tens, and the units.

To subtract multiples of 100 from a three digit number we can take the same two approaches. First we can take a step in the negative direction by 100, for every 100 in our multiple of 100.

So if we have the number 542 - 200, we'll need to take 2 steps of 100 in the negative direction.

542 - 100 = 442, then 442 - 100 = 342.

We can also line up our place values, hundreds, tens, and units and then subtract our ones, tens, and hundreds to find our answer.

Hundreds | Tens | Units | |
---|---|---|---|

$5$5 | $4$4 | $2$2 | |

- | $2$2 | $0$0 | $0$0 |

= | $3$3 | $4$4 | $2$2 |

Watch the following video to see how to do this.

$600-100$600−100

Complete the pattern by subtracting $100$100 each time.

$900$900, $\editable{}$, $\editable{}$, $\editable{}$, $\editable{}$, $\editable{}$

$803-500$803−500

Know forward and backward counting sequences with whole numbers to at least 1000.