Download Mental Addition – Direct Teaching

Objectives:
•
Work out, very quickly, pairs of one-place
decimal numbers with a total of 1, then 10;
•
Add pairs of one-place decimal numbers.
© Hamilton Trust
Keeping Up Term 1
Week 7 Day 1
Quickly write down the pairs of numbers 0-10 that add
to 10. Can you write them all in 1 minute?
Now use the cards below to find pairs to make 1
Can you write them all in 1 minute?
0.1
0.2
0.8
Why is the same number on two cards?
© Hamilton Trust
Keeping Up Term 1
Week 7 Day 1
Which decimal numbers together make 10?
7
0.4
2.6
3.0
10
Use a number line jotting to work out what
goes with 4.3, 6.1, 5.8 and 8.9 to make 10.
© Hamilton Trust
Keeping Up Term 1
Week 7 Day 1
Work in pairs. Repeat this activity five times.
• Write five one-place decimal numbers secretly on your page.
• Take turns to say a one-place decimal number less than 1 to
your partner. For example say 0.6.
• Does this go with any of their numbers to make a whole
number? For example one of their numbers is 8.4, so yes!
• They score the amount they need to add to their number to
make 10. For example 8.4 + 1.6 = 10. Score 1.6.
• Swap roles, with your partner saying a similar number to you.
The winner is the player with the highest score after five goes.
© Hamilton Trust
Keeping Up Term 1
Week 7 Day 1
We use pairs to 1 to add two decimal numbers.
4.6 + 2.7
0.3
0.4
4.6
2.0
5.0
5.3
7.3
Use a number line jotting to work out:
5.5 + 3.6 and 4.7 + 2.8
© Hamilton Trust
Keeping Up Term 1
Week 7 Day 1
Use pairs to 1 and a number line jotting to
solve these calculations:
4.5 + 2.6
6.7 + 1.5
3.8 + 3.3
8.5 + 1.5
5.4 + 3.8
7.6 + 2.7
© Hamilton Trust
Keeping Up Term 1
Week 7 Day 1
Fill in the missing numbers.
1. 4.6 + ☐ = 10
2. 7.2 + ☐ = 10
3. 4.5 + 5.5 = ☐
4. 6.3 + 1.7 = ☐
5. 5.4 + 2.6 = ☐
6. 7.5 + 3.5 = ☐
7. 6.7 + 3.3 = ☐
8. 5.2 + ☐ = 10
9. 8.2 + ☐ = 10
10. 0.6 + ☐ = 1
11. 7.8 + 1.6 = ☐
12. 4.4 + 3.6 = ☐
13. 4.5 + 3.7 = ☐
14. 9.2 + ☐ = 10
© Hamilton Trust
Keeping Up Term 1
Week 7 Day 1