There are different ways to add and subtract larger, 2-digit, numbers, which we look at and discuss, using resources and our Number Facts knowledge.
Here you can find are demonstrations and fun games to practise and improve your Big Numbers Addition and Subtractions.
Add Plus Together All together Sum Total
1. Draw the dienes to show the first number. It is best to start with the largest number.
2. Write an add sign.
3. Draw the dienes to show the the other number.
4. Add and count all the tens.
5. How many tens? Put this in your head
6. then add, count on the ones.
1. Draw the number line and write the first number
(best to start with the largest number in the addition).
2. Do single jumps of +1 to add the other, second number.
3. The number you landed on is the answer.
1. Draw the number line.
2. Write the starting (largest) number at the start of the line (on the left).
3. Using your number bonds jump to the nearest number ending in zero
(nearest multiple of 10, i.e. 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, and so on).
4. Write in the jump how many you jumped by.
5. Look at the number you are adding.
6. How many more ones are still left for you need to add? Add these on.
7. The answer is the final number you land on.
1. Draw the dienes to show the first number
(draw the tens first, then the ones, like in our song).
It is always best to start with the largest number in addition.
2. Do the same with the second number in the addition calculation.
3. Count to add all the tens.
4. Keep that number in your head and continue, now continue counting in ones to add on the ones.
Below are a few demonstrations how to use a number line for a method, that we have practised in school and the children had had the opportunities to consolidate in their Homework.
The method by includes:
1. Draw a number line.
2. Write the largest number on the right hand side of the line.
3. Write the smallest number on the left hand side of the line.
4. From the largest number jump back by 1.
5. Record/write the number you are now at below.
6. Keep jumping back by 1 until you get to the smallest number.
7. The amount of jumps you did is the answer.
1. Draw the dienes to show the FIRST number, which is ALWAYS the LARGEST number.
2. Cross out the same amount of dienes as the number you are subtracting.
3. Count up the amount of dienes you have left.
4. This is your answer.
1. Look at the calculation.
2. Draw the dienes (the sticks of ten and the little ones/units) to show the largest number.
3. Look at the number you are subtracting.
4. Cross out the number of ones dienes.
5. If you run out of ones dienes to cross out then take a stick of ten and exchange/swap it for
ten little ones.
6. Continue to cross these little ones out until you have subtracted all you need to.
7. Add up all the dienes left to find your answer.
1. Draw a number line.
2. Write the largest number on the right hand side.
3. Look at the number you are subtracting. How many tens an d how many ones does it have?
4. Jump back in tens - the number of tens that the number your are subtracting has.
5. Record/write the number on which you land.
6. Then jump back in ones by the same amount of ones as in the number you are subtracting.
7. The number on which you land is the answer.
Finding the DIFFERENCE
1. Look at the first tower and tick the amount of block it contains.
2. Tick this same amount of blocks on the second tower.
3. Count the amount of block on the large tower that have not been ticked.
4. The number of unticked blocks is the answer.
1. Look at the largest number and underline it so you do not go past.
2. Circle the smallest number.
3. Starting at the next number, tick all the numbers up to and including the one you need to stop at.
4. Count up the amount of ticks you have.
WHOLE, PART, PART
1. Look at the numbers underneath the whole box at the top. They are the smaller parts that
add together to make the answer, the whole number (that is also the biggest number).
2. You can draw dienes to show the first number, first part.
(dienes are sticks of tens and little ones)
3. Do the same for the second number, second part.
4. Add all of the tens you have.
5. Add all the ones you have.
6. Add the tens (from step 6) and the ones/units (from step 7) together to get the answer,
the whole number.
* The biggest box is the Whole and contains the biggest number.
* The two boxes below are the Smaller Parts that add up to make the biggest number above,
* You can use your knowledge of Number Bonds for 20 to find the missing part.
1) Think: 15 needs what to make 20?
2) 15 needs 5 to make 20, so the missing number is 5.
* Or you can use a number line to find the missing part, smaller number.
1) Draw a number line and add the part you have (smallest number on the left hand side).
2) Keep adding +1 until you get to the number at the top of the bar model.
3) Count up all the jumps of +1 you have.
4) The amount of jumps is your answer.
1. The biggest box contains the whole, biggest number.
2. The two numbers, the two parts below add up to the biggest whole number above.
3. So, to find the missing number, missing part of the whole, we need to subtract the smallest
number we have from the largest number on top.
4. Draw the dienes to show the largest number, part.
5. Cross out the amount of tens that are in the number you are taking away.
6.Cross out the amount of ones in the number you are taking away.
8. Count up the tens and ones dienes you have left. This is your missing number, missing part.
1. The whole part, largest number is on top.
2. The missing number below will be less than this because it is only a Part of the Whole
3. Subtract the smaller number, smaller part from the largest whole number.
4. Draw the dienes to show the whole number at the top.
5. Cross out the amount of tens dienes sticks of the number you are subtracting from the
dienes you have already drawn.
7. Cross out the amount of ones dienes of the number you are subtracting from the ones
dienes you have already drawn.
8. If you have not got enough ones dienes. Take a tens dienes stick and split it into ten
little ones. Now you will have enough little ones.
9. The amount of dienes you have left is your answer.
More Find the Missing Number
1. Look at the calculation you have.
2. On a number line draw the first number.
3. Do jumps of +1 until you get to the answer that's been given in the calculation.
4. The answer is the amount of jumps you did.