Model 458+277 on an abacus with 4 spikes then find the sum.

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To perform the addition of 458 + 277 on an abacus with 4 spikes, let's break it down step-by-step.

Step 1: Understand the Abacus Layout

An abacus typically has several rods (or spikes) representing different place values:

  1. Units (1s)
  2. Tens (10s)
  3. Hundreds (100s)
  4. Thousands (1000s) (not used in this case)

For our calculation, we will use 4 spikes:

  • Spike 1: Units (1s)
  • Spike 2: Tens (10s)
  • Spike 3: Hundreds (100s)
  • Spike 4: Thousands (not needed in this case)

Step 2: Represent 458 on the Abacus

  1. Hundreds (4): 4 beads on the hundreds spike.
  2. Tens (5): 5 beads on the tens spike.
  3. Units (8): 8 beads on the units spike.

So far, the abacus looks like this:

Spike 1 (Units):   ■■■■■■■■■ (8 beads)
Spike 2 (Tens):    ■■■■■ (5 beads)
Spike 3 (Hundreds): ■■■■ (4 beads)
Spike 4 (Thousands): - (0 beads)

Step 3: Represent 277 on the Abacus

Now, we need to add 277 to our initial representation (458):

  1. Hundreds (2): 2 beads on the hundreds spike.
  2. Tens (7): 7 beads on the tens spike.
  3. Units (7): 7 beads on the units spike.

Step 4: Set Up for Addition

We will add the units, tens, and hundreds separately:

Units:

  • Starting units: 8
  • Adding: 7
  • Total: 15 (which means we write down 5 and carry over 1 to the tens place)

Tens:

  • Starting tens: 5
  • Adding: 7
  • Plus carry over: 1
  • Total: 5 + 7 + 1 = 13 (which means we write down 3 and carry over 1 to the hundreds place)

Hundreds:

  • Starting hundreds: 4
  • Adding: 2
  • Plus carry over: 1
  • Total: 4 + 2 + 1 = 7 (no carry-over since it is less than 10)

Step 5: Final Representation on the Abacus

Now we can represent the final sum, which is:

  • Hundreds (7): 7 beads on the hundreds spike.
  • Tens (3): 3 beads on the tens spike.
  • Units (5): 5 beads on the units spike.

The abacus now looks like this:

Spike 1 (Units):   ■■■■■ (5 beads)
Spike 2 (Tens):    ■■■ (3 beads)
Spike 3 (Hundreds): ■■■■■■■■ (7 beads)
Spike 4 (Thousands): - (0 beads)

Conclusion: Result of 458 + 277

Therefore, the sum of 458 + 277 is 735.