Solve addition problems to 100 by counting on in their heads.
Number Framework Stage 4
- Two sets of different coloured transparent counters.
- Number Strips
Preliminary
The students must realise that last number in a set of tiles gives the number of tiles only if each number has a counter on it. For example there are not 20 counters shown because counters 6 and 10 are missing.
Using Materials
Problem: Josie has 9 toy cars and her mother gives her 4 more as a present. How many toy cars does Josie have?
Write 9 + 4 on the board. The students place 9 counters of one colour on the number strip from 1 to 9. The students have 4 counters of another colour. Before putting them on the strip ask what numbers do they go on, and then what is 9 + 4. The students confirm the answer by placing 4 counters on squares 8, 9, 10, 11. Write the answer on the board.
Examples. (Second number is 5 or less.) Word problems and recording for: 6 + 2, 9 + 2, 7 + 3, 9 + 3, 11 + 4....
Using imaging
Problem: Work out 7 cats plus 4 cats.
Turn the number strip over and encourage the students to imagine 7 counters. Then ask on what squares will the 4 counters go, and so what is 7 + 4. Fold back if necessary by building 1 to 7 in one colour and 8 to 11 in another colour. Encourage the students to count on with their fingers.
Examples. Word stories and recording for: 13 + 2, 11 + 2, 6 + 3, 8 + 4, 11 + 5, 12 + 2....
Imaging Only
Examples. Word stories and recording for: 15 + 3, 8 + 4, 13 + 5, 9 + 3, 7 + 5, 13 + 3, 15 + 4....
Using Number Properties
Provide addition problems in which one first number has two digits and the second number is a single digit below 6. This encourages the use of number properties.
Examples. Word stories and recording for: 75 + 2, 46 + 2, 49 + 2, 53 + 3, 87 + 3, 91 + 4, 67 + 4....