Maths

                                                     W.A.L.T solve problems like 39+_____ = 73

1. 37+42=79
2. 17 +82=99
3. 18+36=54
4. 27+35=62
5. 49+23=72
6. 28+53= 81
7. 37+24=61

I solved these problems by using  a number line. first I went to the tidiest ten and then I jumped to the answer.