The disadvantages of using technology in class are: 1)It hindered students’ ability to communicate with others. 2)It hurts student's critical thinking and their ability to do homework. They might just find the answers online instead of doing it by themselves. 3)Using technology might hinder learning and the educational process. 4)Using technology might be a big destraction to students, students might play games on their laptops instead of listening to teachers. 5)Sometimes, students might loss a lot of time using technology in classroom. They might have connection problems, downloading issues, policing software and other difficulties. 6)It also cost a lot of money for school to buy new technologies.

 The advantages of using technology in class are:1.Using technology in classroom can give interest to students, so they will have a better attendance rates and they will have motivation.2.Using technology can allow many more students to be actively thinking about information, making choices, and executing skills than is typical in teacher-led lessons.3. Using technology in class can improve design skills and attention to audience. 4.Teacher can connect with students easily by using technology. 5. Using technology can save a lot of time on researching.

Advantages and disadvantages of abacus and hand-held calculator

Abacus:

Advantages:
1.Using abacus can help you improve comprehension in math.
2.Using abacus can help you building up better and faster calculation skills.
3.Using abacus can help you improve problem solving skills.
4.Using abacus can help you improve memory.
5.Using abacus can help you improve confidence in math.

Disadvantages:
1.It takes a lot of room in your back pack. It is hard to carry to class.
2.It takes too long to calculate.
3.It is hard to learn.

Hand-held calculator:

Advantages:
1.Using hand-held calculator can allow you to do calculations faster.
2.Using hand-held calculator can allow you to successfully complete more difficult calculations.
3.Using hand-held calculator can give you confidence when you are doing difficult problems.
4.Using hand-held calculator can help you focus on the problems, not the calculations.
5.It is really easy to carry to class, it doen't take a lot of room in your back pack.

Disadvantages:
1.Using hand-held calculator may give you a false sense of confidence in your calculation abilities.
2.Using hand-held calculator might inhibit your ability to do even basic calculations in your head or on paper.

 

Similarities and differences between abacus and calculator

        There are a lot of similarities and differences between an abacus and a hand-held calculator. 
        The similariities between abacus and hand-held calculator are they are both calculating devices, and they both can do multiplication, division, subtraction, and addition properties.
        The differences between abacus and hand-held calculator are 1)Abacus was made in 500 BC., it is really old, but hand-held calculator is made in 1967, it is modern technology device. 2)Abacuse isn't electric it is made by wood, rod, and beads, but hand-held calculator is electric, and some of them use solar power. 3)We don't really use abacus in classroom today, but we use hand-held calculator in class a lot. 4)Abacus doesn't have number on it, it only has beads. But hand-held calculator has number on it.

History of abacus and hand-held calculator

Abacus
        Before calculators were invented, a lot of Asian countries use abacus to calculate. Abacus is an ancient calculating device. It can be used for solving addition, subtraction, division and multiplication problems. It was developed by Chinese, Japanese, and Egyptians in about 500 B.C. Abacus is traced by tray, rod , and beads.

Handheld Calculator
        In 1967, the first hand-held pocket calculator was invented by Jerry D. Merryman, James H. Van Tassel and Jack St. Clair Kilby at Texas Instruments, Incorporated (TI). And in1974 a basic patent for miniature electronic calculators has been issued to Texas Instruments Incorporated. Unlike other old calculater devices. This calculator is really small, easy to carry, and very easy to calculate to solve  math problems.This calculator also leads to the new calculators that we are using now.