Cleo the time traveller is in 1855 at Mary Seacole’s British Hotel in the Crimea, exploring and helping Mary with her maths problems. This time, she will need help to add 2-digit numbers.
More resources for Autumn Block 2 Step 11.
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Discussion points for teachers
1.Help her to work out the answer.
Discuss how partitioning helps us to add 2-digit numbers. Discuss adding the ones first, then the tens, then work out the final total.
25 + 13 = 38 (5 + 3 = 8, 20 + 10 = 30, 30 + 8 = 38)
2.Find three ways to complete the bar model.
Discuss how to use the bar model to help us find the 2-digit numbers that add up to 48. Discuss whether the 2-digit numbers could be the same? How do we know? Discuss how we can find three different ways of completing the bar model. This question is open-ended for the children to explore.
Various answers, for example: 8 + 40, 13 + 35, 10 + 38
3.Help Cleo to use a part-whole model to work out the answer.
Discuss how to use the part-whole model to help add 2-digit numbers.
32 + 45 = 77; Yes there would be enough to feed more than 59 soldiers.
4.Help Cleo to use an addition number sentence to work out the answer.
Discuss whether the linear format helps to add 2-digit numbers or not. Which method could be used to add these 2-digit numbers?
52 + 44 = 96; Yes, Mary has enough eggs for all the soldiers.
National Curriculum Objectives
Mathematics Year 2: (2C2a) Add and subtract numbers mentally, including: a two-digit number and tens
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