Posted in Additive relationships, Calculating, Fluency

# Calculating with target boards 3

Use the target boards to develop fluency.  Use them to:

• recall and remember useful number facts;
• use number facts to calculate mentally;
• explain thinking and methods of calculating.
• use mathematical language correctly. Print Target Board 2

• Say each number out loud.
• Put objects on each number – check that you have the correct amount.
• Say the numbers in order.

Subtraction and the target board.

Choose a number and take away 1. Write a number sentence to show what you have done e.g. 4 – 1 = 3. Use objects to help if you need to. Try taking away other numbers.

Choose two numbers and take the smallest number away from the largest. Write a number sentence to show what you have done.

Choose two numbers and find the difference between the numbers e.g. the difference between 10 and 2 is 8. Use bottle tops to help work this out. Or use the number line. The difference between 2 and 5 is 3.

Find two numbers on the board with a difference of 1.

How do you know you are correct?

How did you work it out? Explain your thinking.

How many pairs of numbers with a difference of 1 can you find? Make a list of the pairs you find.

Practise counting back. Choose two numbers and count back from the larger to the smaller e.g. if you choose 4 and 9, you start at 9 and say 9, 8, 7, 6, 5, 4.

Use a number line to count back. Choose a number on the target board, count back 2, what number are you on now? I chose 10:  10 count back 2 is 8; 10, then 2 less is 8;  10 – 2 = 8

Make up a number story to go with your pairs of numbers, e.g. if you choose 4 and 6 you might say:

“Digit Dog had 6 bones in his dish. He ate 4 of them. How many does he have left?”

“Calculating Cat had 6p in her purse and she spent 4p. How much does she have left?”

“Digit Dog has 6 bones and Calculating Cat has 4. How many more bones does Digit Dog have?”

Make up some problems for someone else to solve.

Problem solving with the target board

My difference is 3 – find two numbers on the target board that have a difference of 3.

I am thinking of two numbers. When I take away the smaller from the larger I am left with 2. What numbers could I be thinking of?

One of my numbers is 7. When I subtract another number, I am left with 5. What is my second number?

I am thinking of a number. I count back 3 and get to 4. What number did I start with? 