13 Calculator memory function
Mastering essential math skills is fundamental to navigating daily life, from balancing a budget to calculating the correct dosage of medication. One of the most useful tools for performing these calculations efficiently is a calculator, especially when it comes equipped with a memory function. Understanding how to use this feature can significantly streamline your mathematical tasks by allowing you to store and recall numbers with ease.
The memory function on a calculator typically includes buttons labeled M+, M-, MR, and MC, each serving a distinct purpose:
M+ (Memory Plus): Adds the current displayed number to the memory.
M- (Memory Minus): Subtracts the current displayed number from the memory.
MR (Memory Recall): Retrieves the stored number from the memory, displaying it on the screen.
MC (Memory Clear): Clears the stored number from the memory.
Example
7×4+3×8
This calculation has several stages.
Both multiplications should be completed before the addition (BIDMAS)
7×4=28
3×8=24
Key in 7×4 then press M+(Memory Plus)
Key in 3×8 then press M+(Memory Plus)
Press MR (Memory Recall)
Answer = 52
Sometimes calculations produce many decimal digits and it is important that you do not round these figures too early in the calculation. Use the memory function.
The calculator may produce a result showing all 9s after the decimal point. e.g. 74.9999999. In this case the result should be rounded to 75 before continuing with the calculation.
NB. You may find your calculator works in a different way.
Activity 37: using the calculator memory
Work through these calculations. Remember to store each stage in the calculator memory.
1) 6 × (3 - 2)
2) 4 - 27 ÷ 9
3) 90 + 50% of 360
4) 8 × 60% of 120
5) 17 × 4 + 3 × 21
6) 17 × (4 + 3) × 21
7) (13.72 ÷ 6.7) × (26.54 ÷ 3.2) (NB Round to 2 decimal places)
Answer
1) 6 × (3 - 2) = 6
2) 4 - 27 ÷ 9 = 1
3) 90 + 50% of 360 = 270
4) 8 × 60% of 120 = 576
5) 17 × 4 + 3 × 21 = 131
6) 17 × (4 + 3) × 21 = 2499
7) (13.72 ÷ 6.7) × (26.54 ÷ 3.2) = 16.98 (2 d.p.)