1. 15+37=?
- 15=10+5 (given on the diagram)
- 37=30+7 (given on the diagram)
- add digits to digits 5+7=12=10+2
- add tens to tens 10+30+10=50
- add tens and digits 50+2=52.
2. 22+49=?
- 22=20+2 (given on the diagram)
- 49=40+9 (given on the diagram)
- add digits to digits 2+9=11=10+1
- add tens to tens 20+40+10=70
- add tens and digits 70+1=71.
3. 38+26=?
- 38=30+8 (given on the diagram)
- 26=20+6 (given on the diagram)
- add digits to digits 8+6=14=10+4
- add tens to tens 30+20+10=60
- add tens and digits 60+4=64.
Answer: 1) 52; 2) 71; 3) 64.
This is how you find the equation for the line
