Place Value Addition by Mele

Mele created this fabulous screencastify to share how she uses her place value knowledge to help her add three digit numbers. She has created a maths story then used this DLO to show how she uses her strategy to find the answer.  I really like the clear way Mele has identified which part of her written answer is her thinking. Great work Mele!

Thinking groups:

Today the Maths thinking groups were challenged to draw on both their number knowledge and strategy knowledge to help them solve this number problem. I was amazed at the use of maths language used as my learners shared their strategies with each other.

Henry's Maths

DON'T SUBTRACT, ADD

1. Moana has $81 and she gives her friend $18. How much money does Moana have left?

18 + 2 = 20

20 + 60 = 80

80 + 1 = 81

       18 + 63 = 81 so 81 - 18 = 63

2. Jake collected $75 from his pocket money to buy a present for his mum. The present only costs $39 so how much change does he have? 
   39 +1=40 
   40+30=70

      70+5=75       

      39 + 36 =75 so 75 - 36=63 ✔

3. Dad takes $93 with him to the fair. He comes back with $57. How much did he spend?

57 +3=60

60 +30=90

90+3=93

so 57+36=93 so 93-57=36✔

At the park the lolly seller has collected in $103.

She has to pay $88 out for buying lollies for the next day. How much money does she have left?

88+2=90

90+10=100

100+3=103

so 103 -88=15✔

4. Sam has $110 and spends $89 on some playstation games he wanted. How much money does he have left?

89+1=90

90=20=110

                                so 110-89=21 ✔

5. I start shopping with $64 and come home with $38. How much did I spend when I was out shopping? 
   38+2=40

     40 +20=60

     60+4=64

     so 64 -38 =26✔

The hard thing was counting in my head.

6. I wanted to collect $100 for charity, but only managed to get $82. How much less than $100 is that? 
   82+8=90

              90+10=100

               so 100-82=18 ✔

We were learning that sometimes we can use our adding strategies to help us solve subtraction questions. I found counting in my head difficult.