Solution: 88+ 10=98
98+ 12= 1 10
Use additive commutative law.
88+ 12= 100
100+ 10= 1 10
Xiaoming has three math problems to do, five English problems to do and two Chinese problems to do. How many questions does he need to do today?
Answer: 3+5=8 8+2=9.
Use additive commutative law.
3+2=5 5+5= 10
3:
Mingming, Honghong and Fangfang have three pencils respectively. Xiaoming gave Fangfang one first, and Honghong gave Fangfang two. How many pencils does Fangfang have now?
3+ 1=4 4+2=6
Use additive commutative law.
3+2=5 5+ 1=6
Grade 3-6, increase the number yourself! Change the names to Xiaoming and Xiaohong.