Young Einstein Mathematics Educational Software Contents

Activity Number 15

Heading : Adding Two 3 Digit Numbers

Description : Adding two 3 digit numbers

Aim/Questions : Add the numbers together.

Educational software theory used:

Adding Two 3 Digit Numbers

When adding two numbers that have a mixture of ones, tens and hundreds in the number you need to do 3 sums.

1.  Firstly add the ones units

2.  Then add the tens units

3.  Finally add the hundreds units

Follow the examples as we go along.

 176 + 248

First add the ones units by adding the 6 and 8 together to get 14

14 is made up of 1 tens unit and 4 ones. Since we are only working with the ones, put down the ones answer in the ones column and add 1 tens unit to the tens column.

 176 + 248 =   1 4

Then add the tens units by adding the 7 and 4 and the 1 carried over together to get 12

Since we are now working with the tens units, put down the ones answer in the tens column and add 1 unit to the hundreds column. 12 is made up of 1 hundreds unit and 2 tens units.

 176 + 248 =   1 24

Finally add the hundreds units by adding the 1 and 2 and the 1 carried over together to get 4.

Since we are now working with the hundreds units, put your final answer in the hundreds column.

 176 + 248 = 424

Educational software Instruction :

1.  Add the two numbers together then type your answer into the ‘Answer Box’ provided.

2.  Press ‘Enter’ when you have finished.

Click on the ‘Wording’ check box if you want the sum written in a sentence.

It might be easier to have backwards entry enabled for this exercise.

Module 15. These Instructions from 'Young Einstein Mathematics educational software by Maths Practice are Copyright. Copyright Maths Practice P/L 2003 ©